Optimal Neutron Source and Beam Shaping Assembly for Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

Vujic, J.; Greenspan, E.; Kastenber, W.E.; Karni, Y.; Regev, D.; Verbeke, J.M.; Leung, K.N.; Chivers, D.; Guess, S.; Kim, L.; Waldron, W.; Zhu, Y.

2003-01-01

There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly

Design of collimator in the radial piercing beam port of Kartini reactor for boron neutron capture therapy

International Nuclear Information System (INIS)

M Ilma Muslih A; Andang Widiharto; Yohannes Sardjono

2014-01-01

Studies were carried out to design a collimator which results in epithermal neutron beam for in vivo experiment of Boron Neutron Capture Therapy (BNCT) at the Kartini Research Reactor by means of Monte Carlo N-Particle (MCNP) codes. Reactor within 100 kW of thermal power was used as the neutron source. All materials used were varied in size, according to the value of mean free path for each material. MCNP simulations indicated that by using 5 cm thick of Ni (95%) as collimator wall, 15 cm thick of Al as moderator, 1 cm thick of Pb as γ-ray shielding, 1.5 cm thick of Boral as additional material, with 2 cm aperture diameter, epithermal neutron beam with maximum flux of 5.03 x 10 8 n.cm -2 .s -1 could be produced. The beam has minimum fast neutron and γ-ray components of, respectively, 2.17 x 10 -13 Gy.cm 2 .n -1 and 1.16 x 10 -13 Gy.cm 2 .n -l , minimum thermal neutron per epithermal neutron ratio of 0.12, and maximum directionality of 0.835 . It did not fully pass the IAEA's criteria, since the epithermal neutron flux was below the recommended value, 1.0 x 10 9 n.cm -2 .s -l . Nonetheless, it was still usable with epithermal neutron flux exceeding 5.0 x 10 8 n.cm -2 .s -1 and fast neutron flux close to 2 x 10 -13 Gy.cm 2 .n -1 it is still feasible for BNCT in vivo experiment. (author)

Design of a boron neutron capture enhanced fast neutron therapy assembly

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhonglu [Georgia Inst. of Technology, Atlanta, GA (United States)

2006-12-01

The use of boron neutron capture to boost tumor dose in fast neutron therapy has been investigated at several fast neutron therapy centers worldwide. This treatment is termed boron neutron capture enhanced fast neutron therapy (BNCEFNT). It is a combination of boron neutron capture therapy (BNCT) and fast neutron therapy (FNT). It is believed that BNCEFNT may be useful in the treatment of some radioresistant brain tumors, such as glioblastoma multiform (GBM). A boron neutron capture enhanced fast neutron therapy assembly has been designed for the Fermilab Neutron Therapy Facility (NTF). This assembly uses a tungsten filter and collimator near the patient's head, with a graphite reflector surrounding the head to significantly increase the dose due to boron neutron capture reactions. The assembly was designed using Monte Carlo radiation transport code MCNP version 5 for a standard 20x20 cm² treatment beam. The calculated boron dose enhancement at 5.7-cm depth in a water-filled head phantom in the assembly with a 5x5 cm² collimation was 21.9% per 100-ppm ¹⁰B for a 5.0-cm tungsten filter and 29.8% for a 8.5-cm tungsten filter. The corresponding dose rate for the 5.0-cm and 8.5-cm thick filters were 0.221 and 0.127 Gy/min, respectively; about 48.5% and 27.9% of the dose rate of the standard 10x10 cm² fast neutron treatment beam. To validate the design calculations, a simplified BNCEFNT assembly was built using four lead bricks to form a 5x5 cm² collimator. Five 1.0-cm thick 20x20 cm² tungsten plates were used to obtain different filter thicknesses and graphite bricks/blocks were used to form a reflector. Measurements of the dose enhancement of the simplified assembly in a water-filled head phantom were performed using a pair of tissue-equivalent ion chambers. One of the ion chambers is loaded with 1000-ppm natural boron (184-ppm ¹⁰B) to measure dose due to boron neutron capture. The

Boron neutron capture therapy (BNCT). Recent aspect, a change from thermal neutron to epithermal neutron beam and a new protocol

International Nuclear Information System (INIS)

Nakagawa, Yoshinobu

1999-01-01

Since 1968, One-hundred seventy three patients with glioblastoma (n=81), anaplastic astrocytoma (n=44), low grade astrocytoma (n=16) or other types of tumor (n=32) were treated by boron-neutron capture therapy (BNCT) using a combination of thermal neutron and BSH in 5 reactors (HTR n=13, JRR-3 n=1, MuITR n=98, KUR n=28, JRR-2 n=33). Out of 101 patients with glioma treated by BNCT under the recent protocol, 33 (10 glioblastoma, 14 anaplastic astrocytoma, 9 low grade astrocytoma) patients lived or have lived longer than 3 years. Nine of these 33 lived or have lived longer than 10 years. According to the retrospective analysis, the important factors related to the clinical results were tumor dose radiation dose and maximum radiation dose in thermal brain cortex. The result was not satisfied as it was expected. Then, we decided to introduce mixed beams which contain thermal neutron and epithermal neutron beams. KUR was reconstructed in 1996 and developed to be available to use mixed beams. Following the shutdown of the JRR-2, JRR-4 was renewed for medical use in 1998. Both reactors have capacity to yield thermal neutron beam, epithermal neutron beam and mixed beams. The development of the neutron source lead us to make a new protocol. (author)

Proton linacs for boron neutron capture therapy

International Nuclear Information System (INIS)

Lennox, A.J.

1993-08-01

Recent advances in the ability to deliver boron-containing drugs to brain tumors have generated interest in ∼4 MeV linacs as sources of epithermal neutrons for radiation therapy. In addition, fast neutron therapy facilities have been studying methods to moderate their beams to take advantage of the high cross section for epithermal neutrons on boron-10. This paper describes the technical issues involved in each approach and presents the motivation for undertaking such studies using the Fermilab linac. the problems which must be solved before therapy can begin are outlined. Status of preparatory work and results of preliminary measurements are presented

Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

International Nuclear Information System (INIS)

Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H.

2014-01-01

The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beams (LAMFI-USP) by the 10 B(p,αγ( 7 Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 10 16 at/cm 2

Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

Energy Technology Data Exchange (ETDEWEB)

Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H. [Institute of Physics, University of São Paulo, SP (Brazil)

2014-11-11

The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beams (LAMFI-USP) by the {sup 10}B(p,αγ({sup 7}Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 10{sup 16} at/cm{sup 2}.

Boron ion irradiation induced structural and surface modification of glassy carbon

International Nuclear Information System (INIS)

Kalijadis, Ana; Jovanović, Zoran; Cvijović-Alagić, Ivana; Laušević, Zoran

2013-01-01

The incorporation of boron into glassy carbon was achieved by irradiating two different types of targets: glassy carbon polymer precursor and carbonized glassy carbon. Targets were irradiated with a 45 keV B 3+ ion beam in the fluence range of 5 × 10 15 –5 × 10 16 ions cm −2 . For both types of targets, the implanted boron was located in a narrow region under the surface. Following irradiation, the polymer was carbonized under the same condition as the glassy carbon samples (at 1273 K) and examined by Raman spectroscopy, temperature programmed desorption, hardness and cyclic voltammetry measurements. Structural analysis showed that during the carbonization process of the irradiated polymers, boron is substitutionally incorporated into the glassy carbon structure, while for irradiated carbonized glassy carbon samples, boron irradiation caused an increase of the sp 3 carbon fraction, which is most pronounced for the highest fluence irradiation. Further analyses showed that different nature of boron incorporation, and thus changed structural parameters, are crucial for obtaining glassy carbon samples with modified mechanical, chemical and electrochemical properties over a wide range

Radio response of human lymphocytes pretreated with boron and gadoliniums assessed by the, comet assay

International Nuclear Information System (INIS)

Kim, J. K.; Park, T. W.; Cebulska-Wasiewska, A.; Nili, M.

2009-01-01

Boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. Neutron beams have often a considerable portion of gamma rays with fast neutrons. Gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. Materials and Methods: The modification of radio response in human lymphocytes pretreated with boron or gadolinium compound was studied by assessing the DNA damage using single cell gel electrophoresis, the comet assay. The lymphocytes from the human peripheral blood were irradiated with 0, 1, 2 and 4 Gy of gamma rays from a 60 Co isotopic source with or without pretreatment of boron or gadolinium compound for 10 minutes at 4 d egree C . Post-irradiation procedures included slide preparation, cell-lysing, unwinding and electrophoresis, neutralization, staining, and analytic steps, gel electrophoresis. Results: The results indicate that pretreatment with boron compound (50 n M or 250 n M of 10 B) is effective in reducing the radiosensitivity of the lymphocyte DNA. Conversely, pretreatment with gadolinium compound (50 n M) led to a dose-dependent increase in the radiosensitivity, most prominently with a dose of 4 Gy (P<0.001). Furthermore, when the lymphocytes were pretreated with a Combined mixture (1:1) of boron (250 n M) and gadolinium (50 n M) compounds, the reduced radiosensitivity was also observed.

Thermoelectric properties of boron and boron phosphide CVD wafers

Energy Technology Data Exchange (ETDEWEB)

Kumashiro, Y.; Yokoyama, T.; Sato, A.; Ando, Y. [Yokohama National Univ. (Japan)

1997-10-01

Electrical and thermal conductivities and thermoelectric power of p-type boron and n-type boron phosphide wafers with amorphous and polycrystalline structures were measured up to high temperatures. The electrical conductivity of amorphous boron wafers is compatible to that of polycrystals at high temperatures and obeys Mott`s T{sup -{1/4}} rule. The thermoelectric power of polycrystalline boron decreases with increasing temperature, while that of amorphous boron is almost constant in a wide temperature range. The weak temperature dependence of the thermal conductivity of BP polycrystalline wafers reflects phonon scattering by grain boundaries. Thermal conductivity of an amorphous boron wafer is almost constant in a wide temperature range, showing a characteristic of a glass. The figure of merit of polycrystalline BP wafers is 10{sup -7}/K at high temperatures while that of amorphous boron is 10{sup -5}/K.

Effect of Hypoeutectic Boron Additions on the Grain Size and Mechanical Properties of Ti-6Al-4V Manufactured with Powder Bed Electron Beam Additive Manufacturing

Science.gov (United States)

Mahbooba, Zaynab; West, Harvey; Harrysson, Ola; Wojcieszynski, Andrzej; Dehoff, Ryan; Nandwana, Peeyush; Horn, Timothy

2017-03-01

In additive manufacturing, microstructural control is feasible via processing parameter alteration. However, the window for parameter variation for certain materials, such as Ti-6Al-4V, is limited, and alternative methods must be employed to customize microstructures. Grain refinement and homogenization in cast titanium alloys has been demonstrated through the addition of hypoeutectic concentrations of boron. This work explores the influence of 0.00 wt.%, 0.25 wt.%, 0.50 wt.%, and 1.0 wt.% boron additions on the microstructure and bulk mechanical properties of Ti-6Al-4V samples fabricated in an Arcam A2 electron beam melting (EBM) system with commercial processing parameters for Ti-6Al-4V. Analyses of EBM fabricated Ti-6Al-4V + B indicate that the addition of 0.25-1.0 wt.% boron progressively refines the grain structure, and it improves hardness and elastic modulus. Despite a reduction in size, the β grain structure remained columnar as a result of directional heat transfer during EBM fabrication.

Boron dose determination for BNCT using Fricke and EPR dosimetry

International Nuclear Information System (INIS)

Wielopolski, L.; Ciesielski, B.

1995-01-01

In Boron Neutron Capture Therapy (BNCT) the dominant dose delivered to the tumor is due to α and 7 Li charged particles resulting from a neutron capture by 10 B and is referred to herein as the boron dose. Boron dose is directly attributable to the following two independent factors, one boron concentration and the neutron capture energy dependent cross section of boron, and two the energy spectrum of the neutrons that interact with boron. The neutron energy distribution at a given point is dictated by the incident neutron energy distribution, the depth in tissue, geometrical factors such as beam size and patient's dimensions. To account for these factors can be accommodated by using Monte Carlo theoretical simulations. However, in conventional experimental BNCT dosimetry, e.g., using TLDs or ionization chambers, it is only possible to estimate the boron dose. To overcome some of the limitations in the conventional dosimetry, modifications in ferrous sulfate dosimetry (Fricke) and Electron Paramagnetic Resonance (EPR) dosimetry in alanine, enable to measure specifically boron dose in a mixed gamma neutron radiation fields. The boron dose, in either of the dosimeters, is obtained as a difference between measurements with boronated and unboronated dosimeters. Since boron participates directly in the measurements, the boron dosimetry reflects the true contribution, integral of the neutron energy spectrum with boron cross section, of the boron dose to the total dose. Both methods are well established and used extensively in dosimetry, they are presented briefly here

Experimental and Simulated Characterization of a Beam Shaping Assembly for Accelerator- Based Boron Neutron Capture Therapy (AB-BNCT)

International Nuclear Information System (INIS)

Burlon, Alejandro A.; Valda, Alejandro A.; Girola, Santiago; Minsky, Daniel M.; Kreiner, Andres J.

2010-01-01

In the frame of the construction of a Tandem Electrostatic Quadrupole Accelerator facility devoted to the Accelerator-Based Boron Neutron Capture Therapy, a Beam Shaping Assembly has been characterized by means of Monte-Carlo simulations and measurements. The neutrons were generated via the 7 Li(p, n) 7 Be reaction by irradiating a thick LiF target with a 2.3 MeV proton beam delivered by the TANDAR accelerator at CNEA. The emerging neutron flux was measured by means of activation foils while the beam quality and directionality was evaluated by means of Monte Carlo simulations. The parameters show compliance with those suggested by IAEA. Finally, an improvement adding a beam collimator has been evaluated.

Evidence for multiple polytypes of semiconducting boron carbide (C2B10) from electronic structure

International Nuclear Information System (INIS)

Lunca-Popa, Petru; Brand, J I; Balaz, Snjezana; Rosa, Luis G; Boag, N M; Bai Mengjun; Robertson, B W; Dowben, P A

2005-01-01

Boron carbides fabricated via plasma enhanced chemical vapour deposition from different isomeric source compounds with the same C 2 B 10 H 12 closo-icosahedral structure result in materials with very different direct (optical) band gaps. This provides compelling evidence for the existence of multiple polytypes of C 2 B 10 boron carbide and is consistent with electron diffraction results

Intraoperative boron neutron capture therapy for malignant gliomas. First clinical results of Tsukuba phase I/II trial using JAERI mixed thermal-epithermal beam

International Nuclear Information System (INIS)

Matsumura, A.; Yamamoto, T.; Shibata, Y.

2000-01-01

Since October 1999, a clinical trial of intraoperative boron neutron capture therapy (IOBNCT) is in progress at JRR-4 (Japan Research Reactor-4) in Japan Atomic Energy Research Institute (JAERI) using mixed thermal-epithermal beam (thermal neutron beam I: TNB-I). Compared to pure thermal beam (thermal neutron beam II: TNB-II), TNB-I has an improved neutron delivery into the deep region than TNB-II. The clinical protocol and the preliminary results will be discussed. (author)

Boron-enhanced diffusion of boron from ultralow-energy boron implantation

International Nuclear Information System (INIS)

Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C.

1998-01-01

The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B + , the threshold implantation dose which leads to BED lies between 3 x 10 14 and of 1 x 10 15 /cm -2 . Formation of the shallowest possible junctions by 0.5 keV B + requires that the implant dose be kept lower than this threshold

Catalytic growth of vertically aligned neutron sensitive 10Boron nitride nanotubes

International Nuclear Information System (INIS)

Ahmad, Pervaiz; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Khan, Ghulamullah; Ramay, Shahid M.; Mahmood, Asif; Amin, Muhammad; Muhammad, Nawshad

2016-01-01

10 Boron nitride nanotubes ( 10 BNNTs) are a potential neutron sensing element in a solid-state neutron detector. The aligned 10 BNNT can be used for its potential application without any further purification. Argon-supported thermal CVD is used to achieve vertically aligned 10 BNNT with the help of nucleation sites produced in a thin layer of magnesium–iron alloy deposited at the top of Si substrate. FESEM shows vertically aligned 10 BNNTs with ball-like catalytic tips at top. EDX reveals magnesium (Mg) contents in the tips that refer to catalytic growth of 10 BNNT. HR-TEM shows tubular morphology of the synthesized 10 BNNT with lattice fringes on its outer part having an interlayer spacing of ∼0.34 nm. XPS shows B 1 s and N 1 s peaks at 190.5 and 398 eV that correspond to hexagonal 10 Boron nitride ( 10 h-BN) nature of the synthesized 10 BNNT, whereas the Mg kll auger peaks at ∼301 and ∼311 eV represents Mg contents in the sample. Raman spectrum has a peak at 1390 (cm −1 ) that corresponds to E 2g mode of vibration in 10 h-BN

Application of adjoint Monte Carlo to accelerate simulations of mono-directional beams in treatment planning for Boron Neutron Capture Therapy

NARCIS (Netherlands)

Nievaart, V.A.; Legrady, D.; Moss, R.L.; Kloosterman, J.L.; Van der Hagen, T.H.; Van Dam, H.

2007-01-01

This paper deals with the application of the adjoint transport theory in order to optimize Monte Carlo based radiotherapy treatment planning. The technique is applied to Boron Neutron Capture Therapy where most often mixed beams of neutrons and gammas are involved. In normal forward Monte Carlo

A novel method for boron determination in rock thin sections : first results from Ngawha

International Nuclear Information System (INIS)

Vickridge, I.C.

1994-01-01

Previous studies of boron in New Zealand rock have relied on whole rock analyses. In order to gain more detailed knowledge of the sources of boron in rocks, we have developed a nuclear probe technique based on the 1 1B(p,α) nuclear reaction. The technique performs well on powdered USGS standards down to below 10 wt. ppm, and we have applied it with a proton beam focused down to 25 x 25 micrometre on a hydrothermally unaltered greywacke from Puketona, near Ngawha, Northland. There appears to be little variation in the boron concentrations in the sedimentary groundmass, but in the veins the boron appears to be more concentrated in the prehnite than in the quartz. (author). 2 tabs., 5 figs., 14 refs

OPTIMIZATION OF THE EPITHERMAL NEUTRON BEAM FOR BORON NEUTRON CAPTURE THERAPY AT THE BROOKHAVEN MEDICAL RESEARCH REACTOR.

Energy Technology Data Exchange (ETDEWEB)

HU,J.P.; RORER,D.C.; RECINIELLO,R.N.; HOLDEN,N.E.

2002-08-18

Clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumor had been carried out for half a decade, using an epithermal neutron beam at the Brookhaven's Medical Reactor. The decision to permanently close this reactor in 2000 cut short the efforts to implement a new conceptual design to optimize this beam in preparation for use with possible new protocols. Details of the conceptual design to produce a higher intensity, more forward-directed neutron beam with less contamination from gamma rays, fast and thermal neutrons are presented here for their potential applicability to other reactor facilities. Monte Carlo calculations were used to predict the flux and absorbed dose produced by the proposed design. The results were benchmarked by the dose rate and flux measurements taken at the facility then in use.

Synthesis and characterization of boron incorporated diamond-like carbon thin films

International Nuclear Information System (INIS)

Zhang, L.L.; Yang, Q.; Tang, Y.; Yang, L.; Zhang, C.; Hu, Y.; Cui, X.

2015-01-01

Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B 4 C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B 4 C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp 3 bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp 3 bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp 3 bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films

In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

International Nuclear Information System (INIS)

Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji

2002-05-01

The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without 10 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of 10 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99±0.24, 3.04±0.19 and 1.43±0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50±0.32, 2.34±0.30 and 2.17±0.28 for ENB, TNB-1 and TNB-2, respectively. The biological effectiveness factor values of the neutron and photon components were 1.22±0.16, 1.23±0.16 and 1.21±0.16, respectively. The depth function of biological effectiveness factor in water phantom and the difference in biological effectiveness factor among boron compounds were also determined. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate biological effectiveness factor as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials. (author)

In vitro biological efficacy of boronated low density lipoproteins for NCT

International Nuclear Information System (INIS)

Kahl, S.B.; Pate, D.; Laster, B.H.; Popenoe, E.A.; Fairchild, R.G.

1992-01-01

Low Density Lipoproteins (LDLs) are known to be internalized within the cell by receptor-mediated mechanisms. There is evidence that LDLs may be taken up avidly by tumor cells to provide cholesterol for the synthesis of cell membrane. Thus, the possibility exists that LDLs may provide an ideal vehicle for the transport of boron to tumor cells for Neutron Capture Therapy (NCT). A boronated analog of LDL has recently been synthesized for possible application in NCT. The analog was tested in cell culture for uptake and biological efficacy in the thermal neutron beam at the Brookhaven Medical Research Reactor (BMRR). It was found that boron concentrations ten times higher than that required for NCT were easily obtained, and that uptake data were constant with a receptor mediated binding mechanism. The measured intracellular concentration of ∼240 μg 10 B/g cells is significantly higher than that obtained with any other boron compound previously evaluated for possible clinical application

Evaluation of selective boron absorption in liver tumors

International Nuclear Information System (INIS)

Chiaraviglio, D.; Grazia, F. De; Zonta, A.; Altieri, S.; Pedroni, P.; Braghieri, B.; Fossati, F.; Pinelli, T.; Perotti, A.; Specchiarello, S.; Perlini, G.; Rief, H.

1988-01-01

The first step was a pharmacokinetic study to identify substances which are good boron transporters and are therefore able to provide a high concentration of the nuclide with respect to the healthy hepatic tissue in the MHN. For this purpose the tumor M5076/73 (M5), which matastasizes spontaneously in liver, was inoculated subcutaneously in a group of C57B1/6 mice. Thirty days after the inoculation, when 90% of the liver was invaded by metastases, a boric acid 0.3 M solution enriched to 96% 10 B was injected into the caudal vein. The mice were sacrificed and the liver was frozen for measurements. Boron concentration in the various samples was achieved by measuring the energy distribution of α particles produced in the nuclear reaction 10 B(n, α) 7 Li induced by a thermal neutron beam extracted from the Triga Mark II reactor,

Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy

International Nuclear Information System (INIS)

Thatar Vento, V.; Bergueiro, J.; Cartelli, D.; Valda, A.A.; Kreiner, A.J.

2011-01-01

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam.

Investigation on the neutron beam characteristics for boron neutron capture therapy with 3D and 2D transport calculations

International Nuclear Information System (INIS)

Kodeli, I.; Diop, C.M.; Nimal, J.C.

1994-01-01

In the framework of future Boron Neutron Capture Therapy (BNCT) experiments, where cells and animals irradiations are planned at the research reactor of Strasbourg University, the feasibility to obtain a suitable epithermal neutron beam is investigated. The neutron fluence and spectra calculations in the reactor are performed using the 3D Monte Carlo code TRIPOLI-3 and the 2D SN code TWODANT. The preliminary analysis of Al 2 O 3 and Al-Al 2 O 3 filters configurations are carried out in an attempt to optimize the flux characteristics in the beam tube facility. 7 figs., 7 refs

Hardness and wear properties of boron-implanted poly(ether-ether-ketone) and poly-ether-imide

International Nuclear Information System (INIS)

Lee Youngchul; Lee, E.H.; Mansur, L.K.

1992-01-01

The effects of boron beam irradiation on the hardness, friction, and wear of polymer surfaces were investigated. Typical high-performance thermoplastics, poly(ether-ether-ketone) (PEEK) and a poly-ether-imide (Ultem) were studied after 200 keV boron ion beam treatment at ambient temperature to doses of 2.3x10 14 , 6.8x10 14 , and 2.2x10 15 ions cm -2 . The hardnesses of pristine and boron-implanted materials were characterized by a conventional Knoop method and a load-depth sensing nanoindentation technique. Both measurements showed a significant increase in hardness with increasing dose. The increase in hardness was also found to depend on the penetration depth of the diamond indenter. Wear and friction properties were characterized by a reciprocating sliding friction tester with an SAE 52100 high-carbon, chrome steel ball at 0.5 and 1 N normal loads. Wear and frictional properties varied in a complex fashion with polymer type and dose, but not much with normal load. A substantial reduction in friction coefficient was observed for PEEK at the highest dose but no reduction was observed for Ultem. The wear damage was substantially reduced at the highest dose for both Ultem and PEEK. For the system studied, the highest dose, 2.2x10 15 ions cm -2 , appears to be optimum in improving wear resistance for both PEEK and Ultem. (orig.)

A technique to prepare boronated B72.3 monoclonal antibody for boron neutron capture therapy

International Nuclear Information System (INIS)

Ranadive, G.N.; Rosenzweig, H.S.; Epperly, M.W.

1993-01-01

B72.3 monoclonal antibody has been successfully boronated using mercaptoundecahydro-closo-dodecaborate (boron cage compound). The reagent was incorporated by first reacting the lysine residues of the antibody with m-maleimidobenzoyl succinimide ester (MBS), followed by Michael addition to the maleimido group by the mercapto boron cage compound to form a physiologically stable thioether linkage. Boron content of the antibody was determined by atomic absorption spectroscopy. For biodistribution studies, boronated antibody was radioiodinated with iodogen. 125 I-labeled and boronated B72.3 monoclonal antibody demonstrated clear tumor localization when administered via tail vein injections to athymic nude mice bearing LS174-T tumor xenografts. Boronated antibody was calculated to deliver 10 6 boron atoms per tumor cell. Although this falls short of the specific boron content originally proposed as necessary for boron neutron capture therapy (BNCT), recent calculations suggest that far fewer atoms of 10 B per tumor cell would be necessary to effect successful BNCT when the boron is targeted to the tumor cell membrane. (author)

Alternative Process for Manufacturing of Thin Layers of Boron for Neutron Measurement

Energy Technology Data Exchange (ETDEWEB)

Auge, Gregoire; Partyka, Stanislas [Onet Technologies (France); Guerard, Bruno; Buffet, Jean-Claude [Institut Laue Langevin - ILL, Grenoble (France)

2015-07-01

detection characteristics, between 0,5 to 5 μm (equivalent to 0,25 to 2.5 massive layer). The thickness is homogenous within a ±20% range. The layer is an almost pure {sup 10}B layer (90%). The ratio of the amount of deposed boron 10 to the amount of raw boron 10 used is more than 80%. Hence, another advantage of this technique is that Boron 10 will be deposited on the cathodes only, without loss of this expensive material. 2 grids of a Multi-Grid detector have been coated with pure Boron by using this technique. The film structure has been analysed with a microscope and the detector has been tested on a monochromatic neutron beam line. Preliminary results will be shown. (authors)

Catalytic growth of vertically aligned neutron sensitive {sup 10}Boron nitride nanotubes

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Pervaiz, E-mail: pervaizahmad@siswa.um.edu.my, E-mail: Pervaiz-pas@yahoo.com; Khandaker, Mayeen Uddin, E-mail: mu-khandaker@yahoo.com, E-mail: mu-khandaker@um.edu.my; Amin, Yusoff Mohd [University of Malaya, Department of Physics, Faculty of Science (Malaysia); Khan, Ghulamullah [University of Malaya, Department of Mechanical Engineering (Malaysia); Ramay, Shahid M. [King Saud University, Department of Physics and Astronomy, College of Science (Saudi Arabia); Mahmood, Asif [King Saud University, Department of Chemical Engineering, College of Engineering (Saudi Arabia); Amin, Muhammad [University of the Punjab, Department of Physics (Pakistan); Muhammad, Nawshad [Interdisciplinary Research Centre in Biomedical Materials (IRCBM) COMSATS Institute of Information Technology (Pakistan)

2016-01-15

{sup 10}Boron nitride nanotubes ({sup 10}BNNTs) are a potential neutron sensing element in a solid-state neutron detector. The aligned {sup 10}BNNT can be used for its potential application without any further purification. Argon-supported thermal CVD is used to achieve vertically aligned {sup 10}BNNT with the help of nucleation sites produced in a thin layer of magnesium–iron alloy deposited at the top of Si substrate. FESEM shows vertically aligned {sup 10}BNNTs with ball-like catalytic tips at top. EDX reveals magnesium (Mg) contents in the tips that refer to catalytic growth of {sup 10}BNNT. HR-TEM shows tubular morphology of the synthesized {sup 10}BNNT with lattice fringes on its outer part having an interlayer spacing of ∼0.34 nm. XPS shows B 1 s and N 1 s peaks at 190.5 and 398 eV that correspond to hexagonal {sup 10}Boron nitride ({sup 10}h-BN) nature of the synthesized {sup 10}BNNT, whereas the Mg kll auger peaks at ∼301 and ∼311 eV represents Mg contents in the sample. Raman spectrum has a peak at 1390 (cm{sup −1}) that corresponds to E{sub 2g} mode of vibration in {sup 10}h-BN.

Meeting the challenge of homogenous boron targeting of heterogeneous tumors for effective boron neutron capture therapy (BNCT)

International Nuclear Information System (INIS)

Heber, Elisa M.; Trivillin, Veronica A.; Itoiz, Maria E.; Rebagliati, J. Raul; Batistoni, Daniel; Kreimann, Erica L.; Schwint, Amanda E.; Nigg, David W.; Gonzalez, Beatriz N.

2006-01-01

BNCT is a tumor cell targeted radiation therapy. Inadequately boron targeted tumor populations jeopardize tumor control. Meeting the to date unresolved challenge of homogeneous targeting of heterogeneous tumors with effective boron carriers would contribute to therapeutic efficacy. The aim of the present study was to evaluate the degree of variation in boron content delivered by boronophenylalanine (BPA), GB-10 (Na 2 10 B 10 H 10 ) and the combined administration of (BPA+GB-10) in different portions of tumor, precancerous tissue around tumor and normal pouch tissue in the hamster cheek pouch oral cancer model. Boron content was evaluated by ICP-AES. The degree of homogeneity in boron targeting was assessed in terms of the coefficient of variation ([S.D./Mean]x100) of boron values. Statistical analysis of the results was performed by one-way ANOVA and the least significant difference test. GB-10 and GB-10 plus BPA achieved respectively a statistically significant 1.8-fold and 3.3-fold increase in targeting homogeneity over BPA. The combined boron compound administration protocol contributes to homogeneous targeting of heterogeneous tumors and would increase therapeutic efficacy of BNCT by exposing all tumor populations to neutron capture reactions in boron. (author)

Response of the oral mucosa to porphyrin mediated boron neutron capture therapy

International Nuclear Information System (INIS)

Morris, G.M.

2003-01-01

Pre-clinical studies are now in progress to develop boron neutron capture therapy (BNCT) modalities for the treatment of head and neck carcinomas. BNCT is a bimodal therapy which involves the administration of a boron-10 enriched compound, that accumulates preferentially in tumours, prior to irradiation with low energy neutrons. These neutrons are captured by boron-10 atoms to produce a highly localised radiation exposure. More recently, it has been demonstrated that various boronated porphyrins can target a variety of tumours. Of the porphyrins evaluated to date, copper tetracarboranylphenyl porphyrin (CuTCPH) is a strong candidate for potential clinical evaluation. It has extremely high specificity for a variety of tumour models. Therapeutic efficacy of CuTCPH mediated BNCT has been demonstrated in pre-clinical studies using the murine EMT-6 carcinoma model. In the present investigation the response of the oral mucosa to CuTCPH mediated boron neutron capture (BNC) irradiation was assessed using a standard rat model (ventral tongue). Single exposure irradiation was carried out on the thermal neutron beam at the Brookhaven Medical Research Reactor, at 3 days after the final injection of the boronated porphyrin. The impact of CuTCPH mediated BNC irradiation on oral mucosa at therapeutically effective exposure times, assessed using the ventral tongue model, was minimal. This was primarily due to the fact that blood boron levels (from CuTCPH) were very low at the time of irradiation. Analysis of the dose-effect data for CuTCPH gave a compound biological effectiveness (CBE) factor of 2.5. It can be concluded that, although, the CBE factor (calculated using blood boron concentrations) was relatively high, CuTCPH mediated BNC irradiation should not cause significant damage at clinically relevant radiation doses. This is because blood boron levels would be very low at the time of irradiation

Boron reclamation

International Nuclear Information System (INIS)

Smith, R.M.

1980-07-01

A process to recover high purity 10 B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron

Design and construction of prompt-gamma spectroscopy facility applied to the boron determination

International Nuclear Information System (INIS)

Poblete, Victor; Henriquez, Carlos; Klein, Juan; Navarro, Gustavo

1996-01-01

A prompt-gamma spectroscopy facility was developed using the south tangential neutron beam of the RECH-1 research reactor for boron determination. The implementation of a thermal neutron beam was performed considering different aspects such as biological protection of working area and the beam collimation for a Ge detector, design and sample holder selection, standards and sample preparation. One ppm of Boron in different samples with counting-rate of 20 minutes and a good accuracy were determined. (author)

Microdosimetry for Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

Maughan, R.L.; Kota, C.

2000-01-01

The specific aims of the research proposal were as follows: (1) To design and construct small volume tissue equivalent proportional counters for the dosimetry and microdosimetry of high intensity thermal and epithermal neutron beams used in BNCT, and of modified fast neutron beams designed for boron neutron capture enhanced fast neutron therapy (BNCEFNT). (2) To develop analytical methods for estimating the biological effectiveness of the absorbed dose in BNCT and BNCEFNT based on the measured microdosimetric spectra. (3) To develop an analytical framework for comparing the biological effectiveness of different epithermal neutron beams used in BNCT and BNCEFNT, based on correlated sets of measured microdosimetric spectra and radiobiological data. Specific aims (1) and (2) were achieved in their entirety and are comprehensively documented in Jay Burmeister's Ph.D. dissertation entitled ''Specification of physical and biologically effective absorbed dose in radiation therapies utilizing the boron neutron capture reaction'' (Wayne State University, 1999). Specific aim (3) proved difficult to accomplish because of a lack of sufficient radiobiological data

Implantation annealing by scanning electron beam

International Nuclear Information System (INIS)

Jaussaud, C.; Biasse, B.; Cartier, A.M.; Bontemps, A.

1983-11-01

Samples of ion implanted silicon (BF 2 , 30keV, 10 15 ions x cm -2 ) have been annealed with a multiple scan electron beam, at temperatures ranging from 1000 to 1200 0 C. The curves of sheet resistance versus time show a minimum. Nuclear reaction measurements of the amount of boron remaining after annealing show that the increase in sheet resistance is due to a loss of boron. The increase in junction depths, measured by spreading resistance on bevels is between a few hundred A and 1000 A [fr

Large animal normal tissue tolerance with boron neutron capture.

Science.gov (United States)

Gavin, P R; Kraft, S L; DeHaan, C E; Swartz, C D; Griebenow, M L

1994-03-30

Normal tissue tolerance of boron neutron capture irradiation using borocaptate sodium (NA2B12H11SH) in an epithermal neutron beam was studied. Large retriever-type dogs were used and the irradiations were performed by single dose, 5 x 10 dorsal portal. Fourteen dogs were irradiated with the epithermal neutron beam alone and 35 dogs were irradiated following intravenous administration of borocaptate sodium. Total body irradiation effect could be seen from the decreased leukocytes and platelets following irradiation. Most values returned to normal within 40 days postirradiation. Severe dermal necrosis occurred in animals given 15 Gy epithermal neutrons alone and in animals irradiated to a total peak physical dose greater than 64 Gy in animals following borocaptate sodium infusion. Lethal brain necrosis was seen in animals receiving between 27 and 39 Gy. Lethal brain necrosis occurred at 22-36 weeks postirradiation. A total peak physical dose of approximately 27 Gy and blood-boron concentrations of 25-50 ppm resulted in abnormal magnetic resonance imaging results in 6 months postexamination. Seven of eight of these animals remained normal and the lesions were not detected at the 12-month postirradiation examination. The bimodal therapy presents a complex challenge in attempting to achieve dose response assays. The resultant total radiation dose is a composite of low and high LET components. The short track length of the boron fission fragments and the geometric effect of the vessels causes much of the intravascular dose to miss the presumed critical target of the endothelial cells. The results indicate a large dose-sparing effect from the boron capture reactions within the blood.

Large animal normal tissue tolerance with boron neutron capture

International Nuclear Information System (INIS)

Gavin, P.R.; Swartz, C.D.; Kraft, S.L.; Briebenow, M.L.; DeHaan, C.E.

1994-01-01

Normal tissue tolerance of boron neutron capture irradiation using borocaptate sodium (NA 2 B 12 H 11 SH) in an epithermal neutron beam was studied. Large retriever-type dogs were used and the irradiations were performed by single dose, 5 x 10 dorsal portal. Fourteen dogs were irradiated with the epithermal neutron beam alone and 35 dogs were irradiated following intravenous administration of borocaptate sodium. Total body irradiation effect could be seen from the decreased leukocytes and platelets following irradiation. Most values returned to normal within 40 days postirradiation. Severe dermal necrosis occurred in animals given 15 Gy epithermal neutrons alone and in animals irradiated to a total peak physical dose greater than 64 Gy in animals following borocaptate sodium infusion. Lethal brain necrosis was seen in animals receiving between 27 and 39 Gy. Lethal brain necrosis occurred at 22-36 weeks postirradiation. A total peak physical dose of approximately 27 Gy and blood-boron concentrations of 25-50 ppm resulted in abnormal magnetic resonance imaging results in 6 months postexamination. Seven of eight of these animals remained normal and the lesions were not detected at the 12-month postirradiation examination. The bimodal therapy presents a complex challenge in attempting to achieve dose response assays. The resultant total radiation dose is a composite of low and high LET components. The short track length of the boron fission fragments and the geometric effect of the vessels causes much of the intravascular dose to miss the presumed critical target of the endothelial cells. The results indicate a large dose-sparing effect from the boron capture reactions within the blood. 23 refs., 6 figs., 2 tabs

Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy.

Science.gov (United States)

Vento, V Thatar; Bergueiro, J; Cartelli, D; Valda, A A; Kreiner, A J

2011-12-01

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam. Copyright © 2011 Elsevier Ltd. All rights reserved.

A New Boron Analysis Method

Energy Technology Data Exchange (ETDEWEB)

Weitman, J; Daaverhoeg, N; Farvolden, S

1970-07-01

In connection with fast neutron (n, {alpha}) cross section measurements a novel boron analysis method has been developed. The boron concentration is inferred from the mass spectrometrically determined number of helium atoms produced in the thermal and epithermal B-10 (n, {alpha}) reaction. The relation between helium amount and boron concentration is given, including corrections for self shielding effects and background levels. Direct and diffusion losses of helium are calculated and losses due to gettering, adsorption and HF-ionization in the release stage are discussed. A series of boron determinations is described and the results are compared with those obtained by other methods, showing excellent agreement. The lower limit of boron concentration which can be measured varies with type of sample. In e.g. steel, concentrations below 10-5 % boron in samples of 0.1-1 gram may be determined.

Hot flow behavior of boron microalloyed steels

International Nuclear Information System (INIS)

Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; El-Wahabi, M.; Cabrera, J.M.

2008-01-01

This research work studies the effect of boron contents on the hot flow behavior of boron microalloyed steels. For this purpose, uniaxial hot-compression tests were carried out in a low carbon steel microalloyed with four different amounts of boron over a wide range of temperatures (950, 1000, 1050 and 1100 deg. C) and constant true strain rates (10 -3 , 10 -2 and 10 -1 s -1 ). Experimental results revealed that both peak stress and peak strain tend to decrease as boron content increases, which indicates that boron additions have a solid solution softening effect. Likewise, the flow curves show a delaying effect on the kinetics of dynamic recrystallization (DRX) when increasing boron content. Deformed microstructures show a finer austenitic grain size in the steel with higher boron content (grain refinement effect). Results are discussed in terms of boron segregation towards austenitic grain boundaries during plastic deformation, which increases the movement of dislocations, enhances the grain boundary cohesion and modificates the grain boundary structure

Effect of elemental composition of ion beam on the phase formation and surface strengthening of structural materials

International Nuclear Information System (INIS)

Avdienko, K.I.; Avdienko, A.A.; Kovalenko, I.A.

2001-01-01

The investigation results are reported on the influence of ion beam element composition on phase formation, wear resistance and microhardness of surface layers of titanium alloys VT-4 and VT-16 as well as stainless steel 12Kh18N10T implanted with nitrogen, oxygen and boron. It is stated that ion implantation into structural materials results in surface hardening and is directly dependent on element composition of implanted ion beam. The presence of oxygen in boron or nitrogen ion beams prevents the formation of boride and nitride phases thus decreasing a hardening effect [ru

Boron thermal/epithermal neutron capture therapy

International Nuclear Information System (INIS)

Fairchild, R.G.

1982-01-01

The development of various particle beams for radiotherapy represents an attempt to improve dose distribution, and to provide high LET radiations which are less sensitive to ambient physical and radiobiological factors such as oxygen tension, cell cycle, and dose rate. In general, a compromise is necessary as effective RBE is reduced in order to spread the dose distribution over the anticipated tumor volume. The approach of delivering stable non-toxic isotopes to tumor, and then activating these atoms subsequently via an external radiation beam has mator advantages; problems associated with high uptake of these isotopes in competing cell pools are obviated, and the general tumor volume can be included in the treatment field of the activating beam. As long as the normal tissues supporting tumor show a low uptake of the isotope to be activated, and as long as the range of the reaction products is short, dose will be restricted to tumor, with a consequent high therapeutic ratio. Neutron Capture Therapy (NCT) is generally carried out by activating boron-10 with low energy neutrons. The range of the high LET, low OER particles from the 10 B(n, α) 7 Li reaction is approx. 10μ, or one cell diameter, a situation that is optimal for cell killing. Significant advantages may be gained by using the NCT procedure in conjunction with improved tissue penetration provided with epithermal or filtered beams, and new compounds showing physiological binding to tumor

Treatment planning figures of merit in thermal and epithermal boron capture therapy of brain tumours

Energy Technology Data Exchange (ETDEWEB)

Wallace, S.A.; Mathur, J.N. (Wollongong Univ., NSW (Australia)); Allen, B.J. (Ansto PMB 1 Menai, NSW (Australia). Biomedicine and Health)

1994-05-01

The boron neutron capture therapy (BNCT) figures of merit of advantage depth, therapeutic depth, modified advantage depth and maximum therapeutic depth have been studied as functions of [sup 10]B tumour to blood ratios and absolute levels. These relationships were examined using the Monte Carlo neutron photon transport code, MCNP, with an ideal 18.4 cm diameter neutron beam incident laterally upon an ellipsoidal neutron photon brain-equivalent model. Mono-energetic beams of 0.025 eV (thermal) and 35 eV (epithermal) were simulated. Increasing the tumour to blood [sup 10]B ratio predictably increases all figures of merit. [sup 10]B concentration was also shown to have a strong bearing on the figures of merit when low levels were present in the system. This is the result of a non-[sup 10]B dependent background dose. At higher levels however, the concentration of [sup 10]B has a diminishing influence. For boron sulphydryl (BSH), little advantage is gained by extending the blood [sup 10]B level beyond 30 ppm, whilst for D, L,-p-boronophenylalanine (BPA) this limit is 10 ppm. Applying the epithermal beam under identical conditions, the therapeutic depth reaches the brain mid-line with a tumour to blood [sup 10]B ratio of only 5.7 for BPA. For BSH, the maximum therapeutic depth reaches the brain mid-line with a tumour to blood ratio of only 1.9 with 30 ppm in the blood. Human data for these compounds are very close to these requirements. (author).

Considerations for boron neutron capture therapy studies

International Nuclear Information System (INIS)

Faria Gaspar, P. de.

1994-01-01

Radiotherapy is indispensable as a mean to eradicate deeply or infiltrating tumor tissue that can not be removed surgically. Therefore, it is not selective and may also kill the surrounding health tissue. The principle of BNCT (Boron Neutron Capture Therapy) consist in targeting a tumor selectively with a boron-10 compound. This nuclide has a large capture cross section for thermal neutrons and the nuclear reaction and the delivered energy in locus will selective the tumor. Since its initial proposal in 1963 BNCT has made much progress, however it is not used in a routine treatment. In this work it was approached some complex procedures, as the obtention of selective boron compounds, the adequate set up of neutron beams, the biodistribution, the in vivo and in vitro studies, and also human patients treatments. This work provide fundamentals about BNCT to professional of different areas of knowledge since it comprises multidisciplinary study. It includes appendixes for the ones not related to the field for a better comprehension of the many aspects involved. It is also presented a glossary containing technical and basic aspects involved. It is also presented a glossary containing technical and basic terms referred in the work. (author). 174 refs, 1 fig, 12 apps

Boron neutron capture therapy for malignant brain tumor and future potential

International Nuclear Information System (INIS)

Nakagawa, Yoshinobu; Hatanaka, Hiroshi.

1994-01-01

This paper presents therapeutic experience with boron neutron capture therapy (BNCT) for malignant brain tumors. Nine patients who survived for 10 years or more as of 1986 are given in a table. A review of the 9 patients concluded that physical dose of 15 Gy is required. In addition, the following factors are defined to be the most important: (1) to determine tumor size and depth as accurately as possible, (2) to measure neutron doses in the deepest site of the tumor during irradiation, (3) to measure the content of boron within the tumor, and to deliver neutron beams as deeply as possible. Finally, the importance of knowing RBE of alpha particles for tumor cells of the human brain is emphasized. (N.K.)

Preparation of new boron compounds with potential for application in 10B NCT: Derivatives of monocarbon carboranes

International Nuclear Information System (INIS)

Morris, J.H.; Khan, S.A.; Mair, F.; Peters, G.

1992-01-01

In order to extend the range and versatility of boron clusters appropriate to NCT the authors have studied routes to derivatives of the anions 1-carba-closo-dodecahydrododecaborate-1, [CB 11 H 12 ] - , (1), and its synthetic precursor, 7-carba-nido-tridecahydroundecaborate-1, [CB 10 H 13 ] - , (2). Substitution chemistry of closo-[CB 11 H 12 ] - and its derivatives had been examined previously primarily with respect to substituents at the C-atom. The different isomeric sites of boron substitution, which have been much less studied, offer potential scope for subtle modification of properties of the substituted species. They have sought to prepare thiol substituted derivatives analogous to the widely studied species [B 12 H 11 SH] 2- . The preliminary experiments to introduce the thiol substituent by routes analogous to those for the preparation of [B 12 H 11 SH] 2- or 1- and 2-[B 10 H 9 SH] 2- were unsuccessful. Therefore they considered routes involving prior substitution of either the precursor nido-[CB 10 H 13 ] - and its derivatives, or the monoboron species used for boron insertion

Titanium reinforced boron-polyimide composite

Science.gov (United States)

Clark, G. A.; Clayton, K. I.

1969-01-01

Processing techniques for boron polyimide prepreg were developed whereby composites could be molded under vacuum bag pressure only. A post-cure cycle was developed which resulted in no loss in room temperature mechanical properties of the composite at any time during up to 16 hours at 650 F. A design utilizing laminated titanium foil was developed to achieve a smooth transition of load from the titanium attachment points into the boron-reinforced body of the structure. The box beam test article was subjected to combined bending and torsional loads while exposed to 650 F. Loads were applied incrementally until failure occurred at 83% design limit load.

Destruction of C60 films by boron ion bombardment

International Nuclear Information System (INIS)

Ren Zhongmin; Du Yuancheng; Ying Zhifeng; Xiong Xiaxing; Li Fuming

1995-01-01

C 60 films are bombarded by 100 keV boron ion beams at doses ranging from 3x10 14 to 1x10 16 /cm 2 . The bombarded films are analyzed using Fourier transform infrared spectroscopy (FTIR), Raman spectra and X-ray diffraction (XRD) measurements. Most C 60 soccer-balls in the implanted region in the films are found to be broken at a dose over 1x10 15 /cm 2 , while at a dose less than 6x10 14 /cm 2 a few C 60 molecules remain undestroyed and maintain some crystal structure. The results of the analyses suggest a complete disintegration of a C 60 molecule under B + bombardment. ((orig.))

Recombination methods for boron neutron capture therapy dosimetry

International Nuclear Information System (INIS)

Golnik, N.; Tulik, P.; Zielczynski, M.

2003-01-01

The radiation effects of boron neutron capture therapy (BNCT) are associated with four-dose-compartment radiation field - boron dose (from 10 B(n,α) 7 Li) reaction), proton dose from 14 N(n,p) 14 C reaction, neutron dose (mainly fast and epithermal neutrons) and gamma-ray dose (external and from capture reaction 1 H(n,γ) 2 D). Because of this the relation between the absorbed dose and the biological effects is very complex and all the above mentioned absorbed dose components should be determined. From this point of view, the recombination chambers can be very useful instruments for characterization of the BNCT beams. They can be used for determination of gamma and high-LET dose components for the characterization of radiation quality of mixed radiation fields by recombination microdosimetric method (RMM). In present work, a graphite high-pressure recombination chamber filled with nitrogen, 10 BF 3 and tissue equivalent gas was used for studies on application of RMM for BNCT dosimetry. The use of these gases or their mixtures opens a possibility to design a recombination chamber for determination of the dose fractions due to gamma radiation, fast neutrons, neutron capture on nitrogen and high LET particles from (n, 10 B) reaction in simulated tissue with different content of 10 B. (author)

Online detection of radiation produced in Boron-10 neutron capture reaction: preliminary studies

International Nuclear Information System (INIS)

Portu, A.; Galván, V.; González, S.J.; Thorp, S.; Santa Cruz, G.; Saint Martin, G.; Blostein, J.J.

2013-01-01

Boron microdistribution in both tumor and normal tissue sections can be studied by the autoradiography technique in solid state nuclear track detectors (SSNTD). A measurement of boron concentration in tissue is obtained through the evaluation of the density of tracks produced by alpha and lithium ions generated in the neutron capture reaction 10B(n,α) 7 Li. This knowledge is pivotal when a BNCT (Boron Neutron Capture Therapy) protocol is considered. A new methodology is proposed in order to record alpha and lithium events in real time, as light spots superimposed to the tissue section image. CCD (Charge-Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) are used as detectors, with the advantage of avoiding the superposition of events. Commercial web cams were employed for the preliminary experiments. They were partially disassembled in order to get the sensor chip uncovered. These devices were exposed to different radiation sources: 6.118 MeV alpha particles (252Cf), 0.662 MeV gamma rays ( 137 Cs) and thermal neutrons (moderated 241 Am-Be source, 103n.cm2.seg-1), to analyze the characteristics of the respective images. Pictures from tissue sections put in contact with the sensor surface were also acquired. A software was developed in Matlab to perform the image capture and processing. Early results show the feasibility of using these devices to study the distribution 10B in tissue samples. (author)

Particle track etch method for analysis of boron in silicon using 10B(n,α)7Li reaction

International Nuclear Information System (INIS)

Chakarvarti, S.K.; Nagpaul, K.K.

1980-01-01

Boron bulk doped p-type (111) silicon thin wafers of different resistivities (1 to 100 ohm-cm +- 20%) have been analysed for boron using cellulose nitrate-Daicel and red dyed LR-115 type II films as detectors of alpha particles from 10 B(n,α) 7 Li reaction. The two detectors measure the same value of boron (approximately 0.1 ppm) in 1 ohm-cm silicon samples and agree closely with the four-point probe electrical resistivity measurement results whereas large discrepancies are observed in case of samples with resistivity > 1 ohm-cm (B concentration 1 ohm-cm. (author)

Boron-containing thioureas for neutron capture therapy

International Nuclear Information System (INIS)

Ketz, H.

1993-01-01

Melanin is produced in large amounts in malignant melanotic melanomas. Because thiourea compounds are covalently incorporated into melanin during its biosynthesis, the preparation of boronated thiourea-derivatives is of particular interest for the BNCT (Boron Neutron Capture Therapy). Accumulation of boron in tumors by means of boronated thiourea-derivatives may therefore provide levels of 10 B which are useful for BNCT. In BNCT the tumor containing the boron compound is irradiated with epithermal neutrons to generate He- and Li-nuclei from the 10 B which can then destroy the tumor cells. Because of the short ranges of these particles (approximately one cell diameter) the damage will be almost exclusively confined to the tumor leaving normal tissue unharmed. High accumulation of 2-mercapto-1-methylimidazole (methimazole) in melanotic melanomas has been described in the literature. Boronated derivatives of methimazole were therefore synthesized. Boron was in the form of a boronic acid, a nido-carbonate and a mercaptoundeca hydro-closo-dodecaborate (BSH). The synthesis of the boron cluster derivatives of methimazole (nido-carborate- and BSH-derivatives) with 9 resp. 12 boron atoms in the molecule were expected to achieve higher concentrations of boron in the tumor than in the case of the boronic acid compound with its single boron atom. (orig.) [de

Deuterated-decaborane using boronization on JT-60U

Energy Technology Data Exchange (ETDEWEB)

Yagyu, Jun-ichi; Arai, Takashi; Kaminaga, Atsushi; Miyata, Katsuyuki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Arai, Masaru [Kaihatsu Denki Co., Ltd., Tokyo (Japan)

2001-03-01

In JT-60U, boronization using hydride-decaborane (B{sub 10}H{sub 14}) vaporization has been conducted for the first wall conditioning. Compared to other discharge cleaning (DC), boronization is claimed to be efficient in reduction of oxygen impurities and hydrogen recycling in plasma. However, there are some problems in reduction of hydrogen included in boron film and stabilization of DC glow discharge during the boronization. To solve these problems, a new boronization method using deuterated-decaborane (B{sub 10}D{sub 14}) was adopted instead of the conventional hydride-decaborane. As a result, hydrogen content in the boron film decreased clearly and discharge conditioning shots, for decreasing hydrogen content in plasmas, after the boronization were reduced to 1/10 in comparison to the conventional process. Furthermore, DC glow discharge became stable, with only helium carrier gas, and it was possible to save 30 hours in maximum of the time necessary to boronization. It is shown that the boronization using deuterated-decaborane is very efficient and effective method for the first wall conditioning. (author)

The study of high-boron steel and high-boron cast iron used for shield

International Nuclear Information System (INIS)

Pan Xuerong; Lu Jixin; Wen Yaozeng; Wang Zhaishu; Cheng Jiantin; Cheng Wen; Shun Danqi; Yu Jinmu

1996-12-01

The smelting, forging, heat-treatment technology and the mechanical properties of three kinds of high-boron steels (type 1: 0.5% boron; type 2: 0.5% boron and 4% or 2% nickel; type 3: 0.5% boron, 0.5% nickel and 0.5% molybdenum) were studied. The test results show that the technology for smelting, forging and heat-treatment (1050 degree C/0.5 h water cooled + 810 degree C/1 h oil cooled) in laboratory is feasible. Being sensitive to notch, the impact toughness of high-boron steel type 1 is not steady and can not meet the technology requirements on mechanical properties. The mechanical properties of both high-boron steel type 2 and type 3 can meet the technological requirements. The smelting technology of high-boron casting iron containing 0.5% boron was researched. The tests show that this casting iron can be smelted in laboratory and its properties can basically satisfy the technology requirements. (10 refs., 6 figs., 11 tab.)

Boron isotopic enrichment by displacement chromatography

International Nuclear Information System (INIS)

Mohapatra, K.K.; Bose, Arun

2014-01-01

10 B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10 B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH) 4 - ) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10 B and 11 B

Medical aspects of boron-slow neutron capture therapy

International Nuclear Information System (INIS)

Sweet, W.H.

1986-01-01

Earlier radiations of patients with cerebral tumors disclosed the need: (1) to find a carrier of the boron compound which would leave the blood and concentrate in the tumor, (2) to use a more penetrating neutron beam, and (3) to develop a much faster method for assaying boron in blood and tissue. To some extent number1 has been accomplished in the form of Na 2 B 12 H 11 SH, number2 has yet to be achieved, and number3 has been solved by the measurement of the 478-keV gamma ray when the 10 B atom disintegrates following its capture of a slow neutron. The hitherto unreported data in this paper describe through the courtesy of Professor Hiroshi Hatanaka his studies on the pharmacokinetics and quality control of Na 2 B 12 H 11 SH based on 96 boron infusions in 86 patients. Simultaneous blood and tumor data are plotted here for 30 patients with glioblastomas (Grade III-IV gliomas), illustrating remarkable variability. Detailed autopsy findings on 18 patients with BNCT showed radiation injury in only 1. Clinical results in 12 of the most favorably situated glioblastomas reveal that 5 are still alive with a 5-year survival rate of 58% and the excellent Karnofsky performance rating of 87%. For the first time evidence is presented that slow-growing astrocytomas may benefit from BNCT. 10 references, 8 figures, 5 tables

An accelerator-based epithermal photoneutron source for boron neutron capture therapy

International Nuclear Information System (INIS)

Mitchell, H.E.

1996-04-01

Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10 7 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF 3 composite and a stacked Al/Teflon design) at various incident electron energies

An accelerator-based epithermal photoneutron source for boron neutron capture therapy

Energy Technology Data Exchange (ETDEWEB)

Mitchell, Hannah E. [Georgia Inst. of Technology, Atlanta, GA (United States)

1996-04-01

Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10⁷ neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF₃ composite and a stacked Al/Teflon design) at various incident electron energies.

Note on boron toxicity in oats

Energy Technology Data Exchange (ETDEWEB)

Langille, W M; Mahoney, J F

1959-01-01

Boron was applied at the rate of 35 pounds per acre of borax to a field of oats. With the first noticeable growth there appeared a definite chlorotic condition of the oat seedlings on plots receiving boron treatments. Analysis of chlorotic tissue at 3 weeks after seeding indicated 110 ppm boron, while apparently healthy tissue contained 6.1 ppm boron at the same stage of growth. There was a rapid decline in the boron content of the oat tissue as the crop grew older. At maturity the oat tissue from the boron-treated plots contained an average of 14.15 ppm boron as compared with 4.10 boron from untreated areas. Boron toxicity had no harmful effect so far as yields were concerned, under the conditions of this experiment. 3 references.

100-nm thick single-phase wurtzite BAlN films with boron contents over 10%

KAUST Repository

Li, Xiaohang; Wang, Shuo; Liu, Hanxiao; Ponce, Fernando A.; Detchprohm, Theeradetch; Dupuis, Russell D.

2017-01-01

Growing thicker BAlN films while maintaining single-phase wurtzite structure and boron content over 10% has been challenging. In this study, we report on the growth of 100 nm-thick single-phase wurtzite BAlN films with boron contents up to 14.4% by MOCVD. Flow-modulated epitaxy was employed to increase diffusion length of group-III atoms and reduce parasitic reactions between the metalorganics and NH3. A large growth efficiency of ∼2000 μm mol−1 was achieved as a result. Small B/III ratios up to 17% in conjunction with high temperatures up to 1010 °C were utilized to prevent formation of the cubic phase and maintain wurtzite structure.

100-nm thick single-phase wurtzite BAlN films with boron contents over 10%

KAUST Repository

Li, Xiaohang

2017-01-11

Growing thicker BAlN films while maintaining single-phase wurtzite structure and boron content over 10% has been challenging. In this study, we report on the growth of 100 nm-thick single-phase wurtzite BAlN films with boron contents up to 14.4% by MOCVD. Flow-modulated epitaxy was employed to increase diffusion length of group-III atoms and reduce parasitic reactions between the metalorganics and NH3. A large growth efficiency of ∼2000 μm mol−1 was achieved as a result. Small B/III ratios up to 17% in conjunction with high temperatures up to 1010 °C were utilized to prevent formation of the cubic phase and maintain wurtzite structure.

Mechanical and Structural Properties of Fluorine-Ion-Implanted Boron Suboxide

OpenAIRE

Machaka, Ronald; Mwakikunga, Bonex W.; Manikandan, Elayaperumal; Derry, Trevor E.; Sigalas, Iakovos; Herrmann, Mathias

2012-01-01

Results on a systematic study on the effects of ion implantation on the near-surface mechanical and structural properties of boron suboxide (B 6O) prepared by uniaxial hot pressing are reviewed. 150keV fluorine ions at fluences of up to 5.0 × 10 16ions/cm 2 were implanted into the ultrahard ceramic material at room temperature and characterized using Raman spectroscopy, atomic force microscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Evidence of ion-beam-as...

Evolution of anisotropy in bcc Fe distorted by interstitial boron

Science.gov (United States)

Gölden, Dominik; Zhang, Hongbin; Radulov, Iliya; Dirba, Imants; Komissinskiy, Philipp; Hildebrandt, Erwin; Alff, Lambert

2018-01-01

The evolution of magnetic anisotropy in bcc Fe as a function of interstitial boron atoms was investigated in thin films grown by molecular beam epitaxy. The thermodynamic nonequilibrium conditions during film growth allowed one to stabilize an interstitial boron content of about 14 at .% accompanied by lattice tetragonalization. The c /a ratio scaled linearly with the boron content up to a maximum value of 1.05 at 300 °C substrate growth temperature, with a room-temperature magnetization of. In contrast to nitrogen interstitials, the magnetic easy axis remained in-plane with an anisotropy of approximately -5.1 ×106erg /cm3 . Density functional theory calculations using the measured lattice parameters confirm this value and show that boron local ordering indeed favors in-plane magnetization. Given the increased temperature stability of boron interstitials as compared to nitrogen interstitials, this study will help to find possible ways to manipulate boron interstitials into a more favorable local order.

Radiobiology of BNCT mediated by GB-10 and GB-10+BPA in experimental oral cancer

Energy Technology Data Exchange (ETDEWEB)

Trivillin, Veronica A.; Heber, Elisa M.; Itoiz, Maria E.; Nigg, David; Calzetta, Osvaldo; Blaumann, Herman; Longhino, Juan; Schwint, Amanda E. E-mail: schwint@cnea.gov.ar

2004-11-01

We previously reported biodistribution and pharmacokinetic data for GB-10 (Na{sub 2}{sup 10}B{sub 10}H{sub 10}) and the combined administration of GB-10 and boronophenylalanine (BPA) as boron delivery agents for boron neutron capture therapy (BNCT) in the hamster cheek pouch oral cancer model. The aim of the present study was to assess, for the first time, the response of hamster cheek pouch tumors, precancerous tissue and normal tissue to BNCT mediated by GB-10 and BNCT mediated by GB-10 and BPA administered jointly using the thermalized epithermal beam of the RA-6 Reactor at the Bariloche Atomic Center. GB-10 exerted 75.5% tumor control (partial+complete remission) with no damage to precancerous tissue around tumor or to normal tissue. Thus, GB-10 proved to be a therapeutically efficient boron agent in this model despite the fact that it is not taken up selectively by oral tumor tissue. GB-10 exerted a selective effect on tumor blood vessels leading to significant tumor control with a sparing effect on normal tissue. BNCT mediated by the combined administration of GB-10 and BPA resulted in a reduction in the dose to normal tissue and would thus allow for significant escalation of dose to tumor without exceeding normal tissue tolerance.

Radiobiology of BNCT mediated by GB-10 and GB-10+BPA in experimental oral cancer

International Nuclear Information System (INIS)

Trivillin, Veronica A.; Heber, Elisa M.; Itoiz, Maria E.; Nigg, David; Calzetta, Osvaldo; Blaumann, Herman; Longhino, Juan; Schwint, Amanda E.

2004-01-01

We previously reported biodistribution and pharmacokinetic data for GB-10 (Na 2 10 B 10 H 10 ) and the combined administration of GB-10 and boronophenylalanine (BPA) as boron delivery agents for boron neutron capture therapy (BNCT) in the hamster cheek pouch oral cancer model. The aim of the present study was to assess, for the first time, the response of hamster cheek pouch tumors, precancerous tissue and normal tissue to BNCT mediated by GB-10 and BNCT mediated by GB-10 and BPA administered jointly using the thermalized epithermal beam of the RA-6 Reactor at the Bariloche Atomic Center. GB-10 exerted 75.5% tumor control (partial+complete remission) with no damage to precancerous tissue around tumor or to normal tissue. Thus, GB-10 proved to be a therapeutically efficient boron agent in this model despite the fact that it is not taken up selectively by oral tumor tissue. GB-10 exerted a selective effect on tumor blood vessels leading to significant tumor control with a sparing effect on normal tissue. BNCT mediated by the combined administration of GB-10 and BPA resulted in a reduction in the dose to normal tissue and would thus allow for significant escalation of dose to tumor without exceeding normal tissue tolerance

Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

Science.gov (United States)

Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H.

2014-11-01

The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beans (LAMFI-USP) by the 10B ( p ,αγ(7Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 1016 at/cm2.

A core laboratory offering full evaluation of new boron compounds. A service to the BNCT community

International Nuclear Information System (INIS)

Zamenhof, R.G.; Patel, H.; Palmer, M.R.; Lin, H.C.; Busse, P.M.; Harling, O.; Binns, P.J.; Riley, K.J.; Bernard, J.

2000-01-01

A joint project by the Beth Israel Deaconess Medical Center at Harvard Medical School and The Nuclear Reactor Laboratory of the Massachusetts Institute of Technology is proposed which would provide a core laboratory for the evaluation of new boron compounds. Federal agency funding has been applied for to support such a facility. The facility's evaluation of candidate boron compounds will include: quantitative cellular boron uptake; cell survival curve analysis (using a thermal neutron beam); small or large animal pharmacokinetic analysis; macro- and micro boron distribution analysis using high-resolution autoradiography, prompt gamma analysis and ICP-AES; small or large animal in vivo tumor control studies (using thermal or epithermal neutron beams); and pharmacological in vivo toxicity evaluation. The laboratory will include small and large animal surgical facilities and resources for additional boron compound chemistry as required by the evaluation procedure. This facility will be open to the BNCT research community. (author)

Quantitative SIMS measurement of high concentration of boron in silicon (up to 20 at.%) using an isotopic comparative method

International Nuclear Information System (INIS)

Dubois, Christiane; Prudon, Gilles; Gautier, Brice; Dupuy, Jean-Claude

2008-01-01

Highly boron doped (up to 20 at.%) silicon samples have been analysed by SIMS with the aim of quantifying the boron concentration in a range where the dilute regime may not be valid any more. An original method is used based on the simultaneous analysis of two different isotopes, namely 10 B and 11 B, in order that the known concentration of the first isotope (initially present with a far lower, constant concentration) is the basis of the quantification of the concentration of the second, present with a very high dose. Argon and oxygen beams have been used and conclusions are drawn about the presence of matrix effects in the case of the analysis of highly doped samples. It appears that only the use of a 8 keV O 2 + beam leads to a significant matrix effect, whereas it is nearly absent in the case of an analysis under 8 keV Ar + beam. The proposed method may be applied to any element showing at least two isotopes in any binary alloys under any primary beam

Biomedical irradiation system for boron neutron capture therapy at the Kyoto University Reactor

International Nuclear Information System (INIS)

Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

1990-01-01

Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

Biomedical irradiation system for boron neutron capture therapy at the Kyoto University reactor

International Nuclear Information System (INIS)

Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

1990-01-01

Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

Physical vapor deposition of cubic boron nitride thin films

International Nuclear Information System (INIS)

Kester, D.J.

1991-01-01

Cubic boron nitride was successfully deposited using physical vapor-deposition methods. RF-sputtering, magnetron sputtering, dual-ion-beam deposition, and ion-beam-assisted evaporation were all used. The ion-assisted evaporation, using boron evaporation and bombardment by nitrogen and argon ions, led to successful cubic boron nitride growth over the widest and most controllable range of conditions. It was found that two factors were important for c-BN growth: bombardment of the growing film and the presence of argon. A systematic study of the deposition conditions was carried out. It was found that the value of momentum transferred into the growing from by the bombarding ions was critical. There was a very narrow transition range in which mixed cubic and hexagonal phase films were prepared. Momentum-per-atom value took into account all the variables involved in ion-assisted deposition: deposition rate, ion energy, ion flux, and ion species. No other factor led to the same control of the process. The role of temperature was also studied; it was found that at low temperatures only mixed cubic and hexagonal material are deposited

Boron-isotope fractionation in plants

Energy Technology Data Exchange (ETDEWEB)

Marentes, E [Univ. of Guelph, Dept. of Horticultural Science, Guelph, Ontario (Canada); Vanderpool, R A [USDA/ARS Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota (United States); Shelp, B J [Univ. of Guelph, Dept. of Horticultural Science, Guelph, Ontario (Canada)

1997-10-15

Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species have been documented, but no determination as to whether plants fractionate the stable isotopes of boron, {sup 11}B and {sup 10}B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in {sup 11}B relative to the nutrient solution, and the leaves were enriched in {sup 10}B and the stem in {sup 11}B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. (author)

Boron-isotope fractionation in plants

International Nuclear Information System (INIS)

Marentes, E.; Vanderpool, R.A.; Shelp, B.J.

1997-01-01

Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species have been documented, but no determination as to whether plants fractionate the stable isotopes of boron, 11 B and 10 B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in 11 B relative to the nutrient solution, and the leaves were enriched in 10 B and the stem in 11 B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. (author)

Laser-induced photochemical enrichment of boron isotopes

International Nuclear Information System (INIS)

Freund, S.M.; Ritter, J.J.

1976-01-01

A boron trichloride starting material containing both boron-10 isotopes and boron-11 isotopes is selectively enriched in one or the other of these isotopes by a laser-induced photochemical method involving the reaction of laser-excited boron trichloride with either H 2 S or D 2 S. The method is carried out by subjecting a low pressure gaseous mixture of boron trichloride starting material and the sulfide to infrared radiation from a carbon dioxide TE laser. The wave length of the radiation is selected so as to selectively excite one or the other of boron-10 BCl 3 molecules or boron-11 BCl 3 molecules, thereby making them preferentially more reactive with the sulfide. The laser-induced reaction produces both a boron-containing solid phase reaction product and a gaseous phase containing mostly unreacted BCl 3 and small amounts of sulfhydroboranes. Pure boron trichloride selectively enriched in one of the isotopes is recovered as the primary product of the method from the gaseous phase by a multi-step recovery procedure. Pure boron trichloride enriched in the other isotope is recovered as a secondary product of the method by the subsequent chlorination of the solid phase reaction product followed by separation of BCl 3 from the mixture of gaseous products resulting from the chlorination

Study of ceramic mixed boron element as a neutron shielding

International Nuclear Information System (INIS)

Ismail Mustapha; Mohd Reusmaazran Yusof; Md Fakarudin Ab Rahman; Nor Paiza Mohamad Hasan; Samihah Mustaffha; Yusof Abdullah; Mohamad Rabaie Shari; Airwan Affandi Mahmood; Nurliyana Abdullah; Hearie Hassan

2012-01-01

Shielding upon radiation should not be underestimated as it can causes hazard to health. Precautions on the released of radioactive materials should be well concerned and considered. Therefore, the combination of ceramic and boron make them very useful for shielding purpose in areas of low and intermediate neutron. A six grades of ceramic tile have been produced namely IMN05 - 5 % boron, IMN06 - 6 % boron, IMN07 - 7 % boron, IMN08 - 8 % boron, IMN09 - 9 % boron, IMN10 - 10 % boron from mixing, press and sintered process. Boron is a material that capable of absorbing and capturing neutron, so that neutron and gamma test were conducted to analyze the effectiveness of boron material in combination with ceramic as shielding. From the finding, percent reduction number of count per minute shows the ceramic tiles are capable to capture neutron. Apart from all the percentage of boron used, 10 % is the most effective shields since the percent reduction indicating greater neutron captured increased. (author)

Pulverization of boron element and proportions of boron carbide in boron

International Nuclear Information System (INIS)

Lang, F.M.; Finck, C.

1956-01-01

It is possible to reduce boron element into fine powder by means of a mortar and pestle made of sintered boron carbide, the ratio of boron carbide introduced being less than one per cent. Boron element at our disposal is made of sharp edged, dark brown, little grains of average size greater than 5 μ. Grain sizes smaller than 1μ are required for applying thin layers of such boron. (author) [fr

Nominal effective radiation doses delivered during clinical trials of boron neutron capture therapy

International Nuclear Information System (INIS)

Capala, J.; Diaz, A.Z.; Chanana, A.D.

1997-01-01

Boron neutron capture therapy (BNCT) is a binary system that, in theory, should selectively deliver lethal, high linear energy transfer (LET) radiation to tumor cells dispersed within normal tissues. It is based on the nuclear reaction 10-B(n, α)7-Li, which occurs when the stable nucleus of boron-10 captures a thermal neutron. Due to the relatively high cross-section of the 10-B nucleus for thermal neutron capture and short ranges of the products of this reaction, tumor cells in the volume exposed to thermal neutrons and containing sufficiently high concentration of 10-B would receive a much higher radiation dose than the normal cells contained within the exposed volume. Nevertheless, radiation dose deposited in normal tissue by gamma and fast neutron contamination of the neutron beam, as well as neutron capture in nitrogen, 14-N(n,p)14-C, hydrogen, 1-H(n,γ)2-H, and in boron present in blood and normal cells, limits the dose that can be delivered to tumor cells. It is, therefore, imperative for the success of the BNCT the dosed delivered to normal tissues be accurately determined in order to optimize the irradiation geometry and to limit the volume of normal tissue exposed to thermal neutrons. These are the major objectives of BNCT treatment planning

Determination of isotopic composition of boron in boron carbide by TIMS and PIGE: an inter-comparison study

International Nuclear Information System (INIS)

Sasibhushan, K.; Rao, R.M.; Parab, A.R.; Alamelu, D.; Aggarwal, S.K.; Acharya, R.; Chhillar, S.; Pujari, P.K.

2015-01-01

The paper reports a comparison of results on the determination of isotopic composition of boron in boron carbide (B 4 C) samples by Thermal Ionisation Mass Spectrometry (TIMS) and Particle Induced Gamma ray Spectrometry (PIGE). B 4 C samples having varying boron isotopic composition (natural, enriched with respect to 10 B) and their synthetic mixtures) have been analysed by both the techniques. The 10 B atom% was found to be in the range of 20-67%. (author)

Effect of boron addition to the hard magnetic bulk Nd60Fe30Al10 amorphous alloy

International Nuclear Information System (INIS)

Kong, H.Z.; Li, Y.; Ding, J.

2000-01-01

A detailed study of the effect of boron addition to crystallinity, magnetic properties and thermal properties was carried out for alloys Nd 60-x Fe 30 Al 10 B x with x=0, 1, 3 and 5 produced by copper mold chill casting and melt-spinning. The cast rods of alloys Nd 60-x Fe 30 Al 10 B x were largely amorphous. Remanence up to 0.154 T and coercivity up to 355 kA/m were observed, which were higher than those of the bulk amorphous Nd 60 Fe 30 Al 10 rod of the same diameter. A step in hysteresis loop was observed for the hard magnetic cast rod and ribbon melt-spun at a low speed of 5 m/s of the alloys with boron addition. Consistent increase in the amplitude of the step and magnetic field (H) at which the step was observed as the boron content increased. A single magnetic phase with low coercivity was observed for fully amorphous ribbon melt-spun at high speed of 30 m/s. Full crystallization due to heat treatment resulted in transition of hard magnetic amorphous phase of Nd 55 Fe 30 Al 10 B 5 cast rod to paramagnetic crystalline phases. TEM results of the as-cast rods illustrated the existence of numerous minute Nd-crystallites in amorphous matrix

Validation and Comparison of the Therapeutic Efficacy of Boron Neutron Capture Therapy Mediated By Boron-Rich Liposomes in Multiple Murine Tumor Models

Directory of Open Access Journals (Sweden)

Charles A Maitz

2017-08-01

Full Text Available Boron neutron capture therapy (BNCT was performed at the University of Missouri Research Reactor in mice bearing CT26 colon carcinoma flank tumors and the results were compared with previously performed studies with mice bearing EMT6 breast cancer flank tumors. Mice were implanted with CT26 tumors subcutaneously in the caudal flank and were given two separate tail vein injections of unilamellar liposomes composed of cholesterol, 1,2-distearoyl-sn-glycer-3-phosphocholine, and K[nido-7-CH3(CH215–7,8-C2B9H11] in the lipid bilayer and encapsulated Na3[1-(2`-B10H9-2-NH3B10H8] within the liposomal core. Mice were irradiated 30 hours after the second injection in a thermal neutron beam for various lengths of time. The tumor size was monitored daily for 72 days. Despite relatively lower tumor boron concentrations, as compared to EMT6 tumors, a 45 minute neutron irradiation BNCT resulted in complete resolution of the tumors in 50% of treated mice, 50% of which never recurred. Median time to tumor volume tripling was 38 days in BNCT treated mice, 17 days in neutron-irradiated mice given no boron compounds, and 4 days in untreated controls. Tumor response in mice with CT26 colon carcinoma was markedly more pronounced than in previous reports of mice with EMT6 tumors, a difference which increased with dose. The slope of the dose response curve of CT26 colon carcinoma tumors is 1.05 times tumor growth delay per Gy compared to 0.09 times tumor growth delay per Gy for EMT6 tumors, indicating that inherent radiosensitivity of tumors plays a role in boron neutron capture therapy and should be considered in the development of clinical applications of BNCT in animals and man.

Structure and reactivity of boron-ate complexes derived from primary and secondary boronic esters.

Science.gov (United States)

Feeney, Kathryn; Berionni, Guillaume; Mayr, Herbert; Aggarwal, Varinder K

2015-06-05

Boron-ate complexes derived from primary and secondary boronic esters and aryllithiums have been isolated, and the kinetics of their reactions with carbenium ions studied. The second-order rate constants have been used to derive nucleophilicity parameters for the boron-ate complexes, revealing that nucleophilicity increased with (i) electron-donating aromatics on boron, (ii) neopentyl glycol over pinacol boronic esters, and (iii) 12-crown-4 ether.

Determination of boron in graphite, boron carbide and glass by ICP-MS, ICP-OES and conventional wet chemical methods

International Nuclear Information System (INIS)

Venkatesh, K.; Kamble, Granthali S.; Venkatesh, Manisha; Kumar, Sanjukta A.; Reddy, A.V.R.

2014-01-01

Boron is an important element of interest in nuclear reactor materials due to its high neutron absorption cross section (σ 0 =3837 barns for 10 B). In the present paper, R and D work and routinely used methods have been described for the analysis of case samples (1) Graphite where boron is present at trace levels, (2) Boron Carbide having boron concentration of about 80% and (3) Glass containing 4-6 % boron. (author)

Introduction to Neutron Coincidence Counter Design Based on Boron-10

Energy Technology Data Exchange (ETDEWEB)

Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

2012-01-22

The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

Production of radioactive molecular beams for CERN-ISOLDE

CERN Document Server

AUTHOR|(SzGeCERN)703149; Kröll, Thorsten

SOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10^11 ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computanional techniques have been used.

Use of the Power Burst Facility for boron neutron capture therapy

International Nuclear Information System (INIS)

Crocker, J.G.; Griebenow, M.L.; Leatham, J.

1990-01-01

A program is under development at the Idaho National Engineering Laboratory (INEL) that involves using the Power Burst Facility (PBF) for research into boron neutron capture therapy (BNCT). BNCT utilizes the ionizing energy from boron-neutron capture to stop reproduction of or destroy cells in cancerous tissue in a two-step process. The first step is to selectively concentrate a boron isotope within the tumor cell, that when activated by neutron capture emits highly ionizing, short range particles. The second step involves activation of the isotope only in the vicinity of the tumor with a narrow neutron beam. The ( 10 B[n, 4 He] 7 Li) reaction with thermal neutrons produces fission products with track lengths approximately equal to a cell diameter. The INEL program includes the modification of the PBF by the addition of a filter and treatment area. The filter will down-scatter high energy neutrons into the epithermal range and remove thermal neutrons and excessively damaging gamma components. The intense source of epithermal neutrons from PBF is considered necessary to achieve optimum therapy for deep-seated tumors with minimum damage to surface tissue. THe neutron filter conceptualized for PBF utilizes aluminum and heavy water to down-scatter neutrons into the proper energy range. Bismuth will be used for gamma shielding and cadmium will remove the thermal neutron contaminant from the beam. The INEL program leads to human clinical trials at PBF which are intended to prove that brain tumors can be successfully treated through noninvasive techniques. Further research into BNCT at PBF for other cancer types is also anticipated

Proceedings of workshop on 'boron science and boron neutron capture therapy'

Energy Technology Data Exchange (ETDEWEB)

Kitaoka, Y. [ed.

1998-12-01

This volume contains the abstracts and programs of the 8th (1996), 9th (1997) and 10th (1998) of the workshop on 'the Boron Science and Boron Neutron Capture Therapy' and the recent progress reports especially subscribed. The 11 of the presented papers are indexed individually. (J.P.N.)

Some thoughts on tolerance, dose, and fractionation in boron neutron capture therapy

International Nuclear Information System (INIS)

Gahbauer, R.; Goodman, J.; Blue, T.

1988-01-01

Unique to boron neutron capture therapy, the tolerance very strongly depends on the boron concentration in normal brain, skin and blood. If one first considers the ideal situation of a 2 KeV beam and a compound clearing from normal tissues and blood, the tolerance dose to epithermal beams relates to the maximum tolerated capture gamma dose and capture high LET dose, H (n,gamma)D and N(n,p) 14 C. The authors can relate this gamma and high LET dose to known clinical experience. Assuming gamma and high LET dose ratios as given by Fairchild and Bond, one may first choose a clearly safe high LET whole brain dose and calculate the unavoidably resulting gamma dose. To a first approximation 500 cGy of high LET dose results in 3,000 cGy gamma dose. One can speculate that this approximates the tolerance of whole brain to the 2 KeV beam with no contributing boron dose if the radiation is fractionated. It would clearly be beyond tolerance in a single fraction where most therapists would be uncomfortable to deliver even one third of the above doses

Biodistribution of Boron compounds in an experimental model of liver metastases for Boron Neutron Capture (BNCT) Studies

International Nuclear Information System (INIS)

Garabalino, Marcela A.; Monti Hughes, Andrea; Molinari, Ana J.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Trivillin, Veronica A.; Schwint, Amanda E.; Nievas, Susana; Aromando, Romina F.

2009-01-01

Boron Neutron Capture Therapy (BNCT) is a binary treatment modality that involves the selective accumulation of 10 B carriers in tumors followed by irradiation with thermal or epithermal neutrons. The high linear energy transfer alpha particles and recoiling 7 Li nuclei emitted during the capture of a thermal neutron by a 10 B nucleus have a short range and a high biological effectiveness. Thus, BNCT would potentially target neoplastic tissue selectively. In previous studies we demonstrated the therapeutic efficacy of different BNCT protocols in an experimental model of oral cancer. More recently we performed experimental studies in normal rat liver that evidenced the feasibility of treating liver metastases employing a novel BNCT protocol proposed by JEC based on ex-situ treatment and partial liver auto-transplant. The aim of the present study was to perform biodistribution studies with different boron compounds and different administration protocols to determine the protocols that would be therapeutically useful in 'in vivo' BNCT studies at the RA-3 Nuclear Reactor in an experimental model of liver metastases in rats. Materials and Methods. A total of 70 BDIX rats (Charles River Lab., MA, USA) were inoculated in the liver with syngeneic colon cancer cells DH/DK12/TRb (ECACC, UK) to induce the development of subcapsular metastatic nodules. 15 days post-inoculation the animals were used for biodistribution studies. A total of 11 protocols were evaluated employing the boron compounds boronophenylalanine (BPA) and GB-10 (Na 2 10 B 1 -0H 10 ), alone or combined employing different doses and administration routes. Tumor, normal tissue and blood samples were processed for boron measurement by ICP-OES. Results. Several protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue, i.e. BPA 15.5 mg 10 B/kg iv + GB-10 50 mg 10 B/kg iv; BPA 46.5 mg 10 B/kg ip; BPA 46.5 mg 10 B/kg ip

Boron Neutron Capture Therapy (BCNT) for the Treatment of Liver Metastases: Biodistribution Studies of Boron Compounds in an Experimental Model

Energy Technology Data Exchange (ETDEWEB)

Marcela A. Garabalino; Andrea Monti Hughes; Ana J. Molinari; Elisa M. Heber; Emiliano C. C. Pozzi; Maria E. Itoiz; Veronica A. Trivillin; Amanda E. Schwint; Jorge E. Cardoso; Lucas L. Colombo; Susana Nievas; David W. Nigg; Romina F. Aromando

2011-03-01

Abstract We previously demonstrated the therapeutic efficacy of different boron neutron capture therapy (BNCT) protocols in an experimental model of oral cancer. BNCT is based on the selective accumulation of 10B carriers in a tumor followed by neutron irradiation. Within the context of exploring the potential therapeutic efficacy of BNCT for the treatment of liver metastases, the aim of the present study was to perform boron biodistribution studies in an experimental model of liver metastases in rats. Different boron compounds and administration conditions were assayed to determine which administration protocols would potentially be therapeutically useful in in vivo BNCT studies at the RA-3 nuclear reactor. A total of 70 BDIX rats were inoculated in the liver with syngeneic colon cancer cells DHD/K12/TRb to induce the development of subcapsular tumor nodules. Fourteen days post-inoculation, the animals were used for biodistribution studies. We evaluated a total of 11 administration protocols for the boron compounds boronophenylalanine (BPA) and GB-10 (Na210B10H10), alone or combined at different dose levels and employing different administration routes. Tumor, normal tissue, and blood samples were processed for boron measurement by atomic emission spectroscopy. Six protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue. Boron concentration values in tumor and normal tissues in the liver metastases model show it would be feasible to reach therapeutic BNCT doses in tumor without exceeding radiotolerance in normal tissue at the thermal neutron facility at RA-3.

Production of radioactive molecular beams for CERN-ISOLDE

Energy Technology Data Exchange (ETDEWEB)

Seiffert, Christoph

2015-06-15

ISOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10{sup 11} ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computational techniques have been used.

A critical assessment of boron target compounds for boron neutron capture therapy.

Science.gov (United States)

Hawthorne, M Frederick; Lee, Mark W

2003-01-01

Boron neutron capture therapy (BNCT) has undergone dramatic developments since its inception by Locher in 1936 and the development of nuclear energy during World War II. The ensuing Cold War spawned the entirely new field of polyhedral borane chemistry, rapid advances in nuclear reactor technology and a corresponding increase in the number to reactors potentially available for BNCT. This effort has been largely oriented toward the eradication of glioblastoma multiforme (GBM) and melanoma with reduced interest in other types of malignancies. The design and synthesis of boron-10 target compounds needed for BNCT was not channeled to those types of compounds specifically required for GBM or melanoma. Consequently, a number of potentially useful boron agents are known which have not been biologically evaluated beyond a cursory examination and only three boron-10 enriched target species are approved for human use following their Investigational New Drug classification by the US Food and Drug Administration; BSH, BPA and GB-10. All ongoing clinical trials with GBM and melanoma are necessarily conducted with one of these three species and most often with BPA. The further development of BNCT is presently stalled by the absence of strong support for advanced compound evaluation and compound discovery driven by recent advances in biology and chemistry. A rigorous demonstration of BNCT efficacy surpassing that of currently available protocols has yet to be achieved. This article discusses the past history of compound development, contemporary problems such as compound classification and those problems which impede future advances. The latter include means for biological evaluation of new (and existing) boron target candidates at all stages of their development and the large-scale synthesis of boron target species for clinical trials and beyond. The future of BNCT is bright if latitude is given to the choice of clinical disease to be treated and if a recognized study

Two-dimensional numerical simulation of boron diffusion for pyramidally textured silicon

International Nuclear Information System (INIS)

Ma, Fa-Jun; Duttagupta, Shubham; Shetty, Kishan Devappa; Meng, Lei; Hoex, Bram; Peters, Ian Marius; Samudra, Ganesh S.

2014-01-01

Multidimensional numerical simulation of boron diffusion is of great relevance for the improvement of industrial n-type crystalline silicon wafer solar cells. However, surface passivation of boron diffused area is typically studied in one dimension on planar lifetime samples. This approach neglects the effects of the solar cell pyramidal texture on the boron doping process and resulting doping profile. In this work, we present a theoretical study using a two-dimensional surface morphology for pyramidally textured samples. The boron diffusivity and segregation coefficient between oxide and silicon in simulation are determined by reproducing measured one-dimensional boron depth profiles prepared using different boron diffusion recipes on planar samples. The established parameters are subsequently used to simulate the boron diffusion process on textured samples. The simulated junction depth is found to agree quantitatively well with electron beam induced current measurements. Finally, chemical passivation on planar and textured samples is compared in device simulation. Particularly, a two-dimensional approach is adopted for textured samples to evaluate chemical passivation. The intrinsic emitter saturation current density, which is only related to Auger and radiative recombination, is also simulated for both planar and textured samples. The differences between planar and textured samples are discussed

Measurement and simulation of the TRR BNCT beam parameters

Energy Technology Data Exchange (ETDEWEB)

Bavarnegin, Elham [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Department of Physics, University of Guilan, Rasht (Iran, Islamic Republic of); Sadremomtaz, Alireza [Department of Physics, University of Guilan, Rasht (Iran, Islamic Republic of); Khalafi, Hossein [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Kasesaz, Yaser, E-mail: ykasesaz@aeoi.org.ir [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Golshanian, Mohadeseh; Ghods, Hossein; Ezzati, Arsalan; Keyvani, Mehdi; Haddadi, Mohammad [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of)

2016-09-11

Recently, the configuration of the Tehran Research Reactor (TRR) thermal column has been modified and a proper thermal neutron beam for preclinical Boron Neutron Capture Therapy (BNCT) has been obtained. In this study, simulations and experimental measurements have been carried out to identify the BNCT beam parameters including the beam uniformity, the distribution of the thermal neutron dose, boron dose, gamma dose in a phantom and also the Therapeutic Gain (TG). To do this, the entire TRR structure including the reactor core, pool, the thermal column and beam tubes have been modeled using MCNPX Monte Carlo code. To measure in-phantom dose distribution a special head phantom has been constructed and foil activation techniques and TLD700 dosimeter have been used. The results show that there is enough uniformity in TRR thermal BNCT beam. TG parameter has the maximum value of 5.7 at the depth of 1 cm from the surface of the phantom, confirming that TRR thermal neutron beam has potential for being used in treatment of superficial brain tumors. For the purpose of a clinical trial, more modifications need to be done at the reactor, as, for example design, and construction of a treatment room at the beam exit which is our plan for future. To date, this beam is usable for biological studies and animal trials. There is a relatively good agreement between simulation and measurement especially within a diameter of 10 cm which is the dimension of usual BNCT beam ports. This relatively good agreement enables a more precise prediction of the irradiation conditions needed for future experiments.

Boron-based nanostructures: Synthesis, functionalization, and characterization

Science.gov (United States)

Bedasso, Eyrusalam Kifyalew

Boron-based nanostructures have not been explored in detail; however, these structures have the potential to revolutionize many fields including electronics and biomedicine. The research discussed in this dissertation focuses on synthesis, functionalization, and characterization of boron-based zero-dimensional nanostructures (core/shell and nanoparticles) and one-dimensional nanostructures (nanorods). The first project investigates the synthesis and functionalization of boron-based core/shell nanoparticles. Two boron-containing core/shell nanoparticles, namely boron/iron oxide and boron/silica, were synthesized. Initially, boron nanoparticles with a diameter between 10-100 nm were prepared by decomposition of nido-decaborane (B10H14) followed by formation of a core/shell structure. The core/shell structures were prepared using the appropriate precursor, iron source and silica source, for the shell in the presence of boron nanoparticles. The formation of core/shell nanostructures was confirmed using high resolution TEM. Then, the core/shell nanoparticles underwent a surface modification. Boron/iron oxide core/shell nanoparticles were functionalized with oleic acid, citric acid, amine-terminated polyethylene glycol, folic acid, and dopamine, and boron/silica core/shell nanoparticles were modified with 3-(amino propyl) triethoxy silane, 3-(2-aminoethyleamino)propyltrimethoxysilane), citric acid, folic acid, amine-terminated polyethylene glycol, and O-(2-Carboxyethyl)polyethylene glycol. A UV-Vis and ATR-FTIR analysis established the success of surface modification. The cytotoxicity of water-soluble core/shell nanoparticles was studied in triple negative breast cancer cell line MDA-MB-231 and the result showed the compounds are not toxic. The second project highlights optimization of reaction conditions for the synthesis of boron nanorods. This synthesis, done via reduction of boron oxide with molten lithium, was studied to produce boron nanorods without any

Fluorescent converter and neutron absorber being made of boron nitride

International Nuclear Information System (INIS)

Matsumoto, G.; Teramura, M.; Sato, J.; Maeda, M.

1983-01-01

To improve the sensitivity of fluorescent converter is essential to the neutron radiography (NRG) which utilizes portable, not so strong, neutron sources. The fluorescent converter made of boron nitride (BN) is fabricated and tested. The sensitivity is about 1/20 of the NE426, but the homogeneity may be better. If 10 BN is utilized, the sensitivity will be five times as much as that of natural BN. Using the neutron beam of the Kyoto University Research Reactor, the flux of which is about 10 6 n/cm 2 sec, a good neutron television image was gained by X-ray television camera. As a bi-product of this converter, a flexible absorber was fabricated. (Auth.)

Monitoring of blood-10B concentration for boron neutron capture therapy using prompt gamma-ray analysis

International Nuclear Information System (INIS)

Raaijmakers, C.P.J.; Konijnenberg, M.W.; Dewit, L.; Mijnheer, B.J.; Haritz, D.; Huiskamp, R.; Philipp, K.; Siefert, A.; Stecher-Rasmussen, F.

1995-01-01

The aim of the present study was to monitor the blood- 10 B concentration of laboratory dogs receiving boron neutron capture therapy, in order to obtain optimal agreement between prescribed and actual dose. A prompt gamma-ray analysis system was developed for this purpose at the High Flux Reactor in Petten. The technique was compared with inductively coupled plasma-atomic emission spectrometry and showed good agreement. A substantial variation in 10 B clearance pattern after administration of borocaptate sodium was found between the different dogs. Consequently, the irradiation commencement was adjusted to the individually determined boron elimination curve. Mean blood- 10 B concentratios during irradiation of 25.8±2.2 μg/g (1 SD, n=18) and 49.3±5.3 μg/g (1 SD, n=17) were obtained for intended concentrations of 25 μg/g and 50 μg/g, respectively. These variations are a factor of two smaller than irradiations performed at a uniform post-infusion irradiation starting time. Such a careful bolld- 10 B monitoring procedure is a prerequisite for accurately obtaining such steep dose-response curves as observed during the dog study. (orig.)

The preparation of high-adsorption, spherical, hexagonal boron nitride by template method

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ning, E-mail: zhangning5832@163.com; Liu, Huan; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Zhou, Yonghui

2014-11-15

Highlights: • The high-adsorption, spherical, hexagonal boron nitride powders were prepared. • The influence mechanism of template content on the micro-morphology and adsorption was explored. • At appropriate synthesis temperature, higher adsorption mesoporous spheres h-BN began to form. - Abstract: This research used low-cost boric acid and borax as a source of boron, urea as a nitrogen source, dodecyl-trimethyl ammonium chloride (DTAC) as a template, and thus prepared different micro-morphology hexagonal boron nitride powders under a flowing ammonia atmosphere at different nitriding temperatures. The effects of the template content and nitriding temperature on the micro-morphology of hexagonal boron nitride were studied and the formation mechanism analysed. The influences of the template content and nitriding temperature on adsorption performance were also explored. The results showed that at a nitriding temperature of 675 °C, the micro-morphologies of h-BN powder were orderly, inhomogeneous spherical, uniform spherical, beam, and pie-like with increasing template content. The micro-morphology was inhomogeneous spherical at a DTAC dose of 7.5%. The micro-morphology was uniform spherical at a DTAC dose of 10%. At a DTAC dose of 12%, the micro-morphology was a mixture of beam and pie-like shapes. At a certain template content (DTAC at 10%) and at lower nitriding temperatures (625 °C and 650 °C), spherical shell structures with surface subsidence began to form. The porous spheres would appear at a nitriding temperature of 675 °C, and the ball diameter thus formed was approximately 500–600 nm. The ball diameter was about 600–700 nm when the nitriding temperature was 700 °C. At a nitriding temperature of 725 °C, the ball diameter was between 800 and 1000 nm and sintering necking started to form. When the relative pressure was higher, previously closed pores opened and connected with the outside world: the adsorption then increased significantly. The

White-Beam X-ray Diffraction and Radiography Studies on High-Boron Containing Borosilicate Glass at High Pressures

Science.gov (United States)

Ham, Kathryn; Vohra, Yogesh; Kono, Yoshio; Wereszczak, Andrew; Patel, Parimal

Multi-angle energy-dispersive x-ray diffraction studies and white-beam x-ray radiography were conducted with a cylindrically shaped (1 mm diameter and 0.7 mm high) high-boron content borosilicate glass sample (17.6% B2O3) to a pressure of 13.7 GPa using a Paris-Edinburgh (PE) press at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The measured structure factor S(q) to large q = 19 Å-1, is used to determine information about the internuclear bond distances between various species of atoms within the glass sample. Sample pressure was determined with gold as a pressure standard. The sample height as measured by radiography showed an overall uniaxial compression of 22.5 % at 13.7 GPa with 10.6% permanent compaction after decompression to ambient conditions. The reduced pair distribution function G(r) was extracted and Si-O, O-O, and Si-Si bond distances were measured as a function of pressure. Raman spectroscopy of pressure recovered sample as compared to starting material showed blue-shift and changes in intensity and widths of Raman bands associated with silicate and B3O6 boroxol rings. US Army Research Office under Grant No. W911NF-15-1-0614.

Highly-focused boron implantation in diamond and imaging using the nuclear reaction {sup 11}B(p, α){sup 8}Be

Energy Technology Data Exchange (ETDEWEB)

Ynsa, M.D., E-mail: m.ynsa@uam.es [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física Aplicada, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Ramos, M.A. [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física de la Materia Condensada and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Skukan, N. [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Torres-Costa, V. [Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Departamento de Física Aplicada, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Jakšić, M. [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia)

2015-04-01

Diamond is an especially attractive material because of its gemological value as well as its unique mechanical, chemical and physical properties. One of these properties is that boron-doped diamond is an electrically p-type semiconducting material at practically any boron concentration. This property makes it possible to use diamonds for multiple industrial and technological applications. Boron can be incorporated into pure diamond by different techniques including ion implantation. Although typical energies used to dope diamond by ion implantation are about 100 keV, implantations have also been performed with energies above MeV. In this work CMAM microbeam setup has been used to demonstrate capability to implant boron with high energies. An 8 MeV boron beam with a size of about 5 × 3 μm{sup 2} and a beam current higher than 500 pA has been employed while controlling the beam position and fluence at all irradiated areas. The subsequent mapping of the implanted boron in diamond has been obtained using the strong and broad nuclear reaction {sup 11}B(p, α){sup 8}Be at E{sub p} = 660 keV. This reaction has a high Q-value (8.59 MeV for α{sub 0} and 5.68 MeV for α{sub 1}) and thus is almost interference-free. The sensitivity of the technique is studied in this work.

Density separation of boron particles. Final report

International Nuclear Information System (INIS)

Smith, R.M.

1980-04-01

A density distribution much broader than expected was observed in lots of natural boron powder supplied by two different sources. The material in both lots was found to have a rhombohedral crystal structure, and the only other parameters which seemed to account for such a distribution were impurities within the crystal structure and varying isotopic ratios. A separation technique was established to isolate boron particles in narrow densty ranges. The isolated fractions were subsequently analyzed for B 10 and total boron content in an effort to determine whether selective isotopic enrichment and nonhomogeneous impurity distribution were the causes for the broad density distribution of the boron powders. It was found that although the B 10 content remained nearly constant around 18%, the total boron content varied from 37.5 to 98.7%. One of the lots also was found to contain an apparently high level of alpha rhombohedral boron which broadened the density distribution considerably. During this work, a capability for removing boron particles containing gross amounts of impurities and, thereby, improving the overall purity of the remaining material was developed. In addition, the separation technique used in this study apparently isolated particles with alpha and beta rhombohedral crystal structures, although the only supporting evidence is density data

Surface modification of the hard metal tungsten carbide-cobalt by boron ion implantation

International Nuclear Information System (INIS)

Mrotchek, I.

2007-01-01

In the present thesis ion beam implantation of boron is studied as method for the increasement of the hardness and for the improvement of the operational characteristics of cutting tools on the tungsten carbide-cobalt base. For the boron implantation with 40 keV energy and ∼5.10 17 ions/cm 2 fluence following topics were shown: The incoerporation of boron leads to a deformation and remaining strain of the WC lattice, which possesses different stregth in the different directions of the elementary cell. The maximum of the deformation is reached at an implantation temperature of 450 C. The segregation of the new phases CoWB and Co 3 W was detected at 900 C implantation temperature. At lower temperatures now new phases were found. The tribological characteristics of WC-Co are improved. Hereby the maxiaml effect was measured for implantation temperatures from 450 C to 700 C: Improvement of the microhardness by the factor 2..2.5, improvement of the wear resistance by the factor 4. The tribological effects extend to larger depths than the penetration depth of the boron implantation profile. The detected property improvements of the hard metal H3 show the possibility of a practical application of boron ion implantation in industry. The effects essential for a wer decreasement are a hardening of the carbide phase by deformation of the lattice, a hardening of the cobalt binding material and the phase boundaries because of the formation of a solid solution of the implanted boron atoms in Co and by this a blocking of the dislocation movement and the rupture spreading under load

Boron nitride stamp for ultra-violet nanoimprinting lithography fabricated by focused ion beam lithography

International Nuclear Information System (INIS)

Altun, Ali Ozhan; Jeong, Jun-Ho; Rha, Jong-Joo; Kim, Ki-Don; Lee, Eung-Sug

2007-01-01

Cubic boron nitride (c-BN) is one of the hardest known materials (second after diamond). It has a high level of chemical resistance and high UV transmittance. In this study, a stamp for ultra-violet nanoimprint lithography (UV-NIL) was fabricated using a bi-layered BN film deposited on a quartz substrate. Deposition of the BN was done using RF magnetron sputtering. A hexagonal boron nitride (h-BN) layer was deposited for 30 min before c-BN was deposited for 30 min. The thickness of the film was measured as 160 nm. The phase of the c-BN layer was investigated using Fourier transform infrared (FTIR) spectrometry, and it was found that the c-BN layer has a 40% cubic phase. The deposited film was patterned using focused ion beam (FIB) lithography for use as a UV-NIL stamp. Line patterns were fabricated with the line width and line distance set at 150 and 150 nm, respectively. The patterning process was performed by applying different currents to observe the effect of the current value on the pattern profile. The fabricated patterns were investigated using AFM, and it was found that the pattern fabricated by applying a current value of 50 picoamperes (pA) has a better profile with a 65 nm line depth. The UV transmittance of the 160 nm thick film was measured to be 70-86%. The hardness and modulus of the BN was measured to be 12 and 150 GPa, respectively. The water contact angle of the stamp surface was measured at 75 0 . The stamp was applied to UV-NIL without coating with an anti-adhesion layer. Successful imprinting was proved via scanning electron microscope (SEM) images of the imprinted resin

Boron removal by electrocoagulation and recovery.

Science.gov (United States)

Isa, Mohamed Hasnain; Ezechi, Ezerie Henry; Ahmed, Zubair; Magram, Saleh Faraj; Kutty, Shamsul Rahman Mohamed

2014-03-15

This work investigated the removal of boron from wastewater and its recovery by electrocoagulation and hydrothermal mineralization methods respectively. The experimental design was developed using Box-Behnken Model. An initial study was performed based on four preselected variables (pH, current density, concentration and time) using synthetic wastewater. Response surface methodology (RSM) was used to evaluate the effect of process variables and their interaction on boron removal. The optimum conditions were obtained as pH 6.3, current density 17.4 mA/cm(2), and time 89 min. At these applied optimum conditions, 99.7% boron removal from an initial concentration of 10.4 mg/L was achieved. The process was effectively optimized by RSM with a desirability value of 1.0. The results showed that boron removal efficiency enhanced with increase in current density and treatment time. Removal efficiency also increased when pH was increased from 4 to 7 and subsequently decreased at pH 10. Adsorption kinetics study revealed that the reaction followed pseudo second order kinetic model; evidenced by high correlation and goodness of fit. Thermodynamics study showed that mechanism of boron adsorption was chemisorption and the reaction was endothermic in nature. Furthermore, the adsorption process was spontaneous as indicated by negative values of the adsorption free energy. Treatment of real produced water using electrocoagulation resulted in 98% boron removal. The hydrothermal mineralization study showed that borate minerals (Inyoite, Takadaite and Nifontovite) can be recovered as recyclable precipitate from electrocoagulation flocs of produced water. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optical properties of boron carbide near the boron K edge evaluated by soft-x-ray reflectometry from a Ru/B4C multilayer

Energy Technology Data Exchange (ETDEWEB)

Ksenzov, Dmitriy; Panzner, Tobias; Schlemper, Christoph; Morawe, Christian; Pietsch, Ullrich

2009-12-10

Soft-x-ray Bragg reflection from two Ru/B4C multilayers with 10 and 63 periods was used for independent determination of both real and imaginary parts of the refractive index n = 1 -{delta} + i{beta} close to the boron K edge ({approx}188 eV). Prior to soft x-ray measurements, the structural parameters of the multilayers were determined by x-ray reflectometry using hard x rays. For the 63-period sample, the optical properties based on the predictions made for elemental boron major deviations were found close to the K edge of boron for the 10-period sample explained by chemical bonding of boron to B4C and various boron oxides.

Tumor cell killing effect of boronated dipeptide. Boromethylglycylphenylalanine on boron neutron capture therapy for malignant brain tumors

International Nuclear Information System (INIS)

Takagaki, Masao; Ono, Koji; Masunaga, Shinichiro; Kinashi, Yuko; Kobayashi, Toru; Oda, Yoshifumi; Kikuchi, Haruhiko; Spielvogel, B.F.

1994-01-01

The killing effect of Boron Neutron Capture Therapy; BNCT, is dependant on the boron concentration ratio of tumor to normal brain (T/N ratio), and also that of tumor to blood (T/B ratio). The clinical boron carrier of boro-captate (BSH) showed the large T/N ratio of ca. 8, however the T/B ratio was around 1, which indicated nonselective accumulation into tumor. Indeed high boron concentration of blood restrict the neutron irradiation dose in order to circumvent the normal endothelial damage, especially in the case of deeply seated tumor. Phenylalanine analogue of para borono-phenylalanine (BPA) is an effective boron carrier on BNCT for malignant melanoma. For the BNCT on brain tumors, however, BPA concentration in normal brain was reported to be intolerably high. In order to improve the T/N ratio of BPA in brain, therefore, a dipeptide of boromethylglycylphenylalanine (BMGP) was synthesized deriving from trimethylglycine conjugated with BPA. It is expected to be selectively accumulated into tumor with little uptake into normal brain. Because a dipeptide might not pass through the normal blood brain barrier (BBB). Its killing effect on cultured glioma cell, T98G, and its distribution in rat brain bearing 9L glioma have been investigated in this paper. The BNCT effect of BMGP on cultured cells was nearly triple in comparison with DL-BPA. The neutron dose yielding 1% survival ratio were 7x10 12 nvt for BMGP and 2x10 13 nvt for BPA respectively on BNCT after boron loading for 16 hrs in the same B-10 concentration of 20ppm. Quantitative study of boron concentration via the α-auto radiography and the prompt gamma ray assay on 9L brain tumor rats revealed that T/N ratio and T/B ratio are 12.0 and 3.0 respectively. Those values are excellent for BNCT use. (author)

A DMS kinetic study of the boron oxides vapor in the combustion front of SHS system Mo + B

International Nuclear Information System (INIS)

Kashireninov, O.E.; Yuranov, I.A.

1994-01-01

The distribution of the boron oxides vapor in the combustion wave of the SHS system Mo + B has been studied by the dynamic mass spectrometry technique (DMS) to test the thermodynamically based hypothesis for the key role of gas-phase transport in solid-state combustion. The molecular beam sampling of the gases over the burning tablet was performed by a stationary probe cone from the moving combustion wave. Ion currents of boron oxides were recorded at 10--20 ms intervals that afforded spatial resolution of 0.1--0.2 mm. It has been found that the distribution of the boron oxides vapor pressure along the combustion wave corresponds to the known zones of preheating, reaction, and postcombustion. The rapid increase of B 2 O 2 pressure takes place in the preheating zone as a result of the reaction B(s) + B 2 O 3 (g) = B 2 O 2 (g). Boron oxides are not observed over the reaction zone because of their complete decay in the reaction with Mo(s) to form molybdenum boride(s). The appearance The appearance of boron oxide vapors over the postcombustion zone is due to the evaporation of B 2 O 3 (l). The effective kinetic parameters are estimated from the data obtained. The results show that solid-state combustion of the Mo + B system proceeds predominantly through formation of gas-phase boron oxides

Helium diffusion in irradiated boron carbide

International Nuclear Information System (INIS)

Hollenberg, G.W.

1981-03-01

Boron carbide has been internationally adopted as the neutron absorber material in the control and safety rods of large fast breeder reactors. Its relatively large neutron capture cross section at high neutron energies provides sufficient reactivity worth with a minimum of core space. In addition, the commercial availability of boron carbide makes it attractive from a fabrication standpoint. Instrumented irradiation experiments in EBR-II have provided continuous helium release data on boron carbide at a variety of operating temperatures. Although some microstructural and compositional variations were examined in these experiments most of the boron carbide was prototypic of that used in the Fast Flux Test Facility. The density of the boron carbide pellets was approximately 92% of theoretical. The boron carbide pellets were approximately 1.0 cm in diameter and possessed average grain sizes that varied from 8 to 30 μm. Pellet centerline temperatures were continually measured during the irradiation experiments

Boron

Science.gov (United States)

Boron is an essential micronutrient element required for plant growth. Boron deficiency is wide-spread in crop plants throughout the world especially in coarse-textured soils in humid areas. Boron toxicity can also occur, especially in arid regions under irrigation. Plants respond directly to the...

SU-F-T-183: Design of a Beam Shaping Assembly of a Compact DD-Based Boron Neutron Capture Therapy System

Energy Technology Data Exchange (ETDEWEB)

Hsieh, M; Liu, Y; Nie, L [Purdue University, West Lafayette, Indiana (United States)

2016-06-15

Purpose: To design a beam shaping assembly (BSA) to shape the 2.45-MeV neutrons produced by a deuterium-deuterium (DD) neutron generator and to optimize the beam output for boron neutron capture therapy of brain tumors Methods: MCNP is used for this simulation study. The simulation model consists of a neutron surface source that resembles an actual DD source and is surrounded by a BSA. The neutron source emits 2.45-MeV neutrons isotropically. The BSA is composed of a moderator, reflector, collimator and filter. Various types of materials and geometries are tested for each component to optimize the neutron output. Neutron characteristics are measured with an 2×2×2-cm{sup 3} air-equivalent cylinder at the beam exit. The ideal BSA is determined by evaluating the in-air parameters, which include epithermal neutron per source neutron, fast neutron dose per epithermal neutron, and photon dose per epithermal neutron. The parameter values are compared to those recommended by the IAEA. Results: The ideal materials for reflector and thermal neutron filter were lead and cadmium, respectively. The thickness for reflector was 43 cm and for filter was 0.5 mm. At present, the best-performing moderator has 25 cm of AlF{sub 3} and 5 cm of MgF{sub 2}. This layout creates a neutron spectrum that has a peak at approximately 10 keV and produces 1.35E-4 epithermal neutrons per source neutron per cm{sup 2}. Additional neutron characteristics, fast neutrons per epithermal neutron and photon per epithermal neutron, are still under investigation. Conclusion: Working is ongoing to optimize the final layout of the BSA. The neutron spectrum at the beam exit window of the final configuration will have the maximum number of epithermal neutrons and limited photon and fast neutron contaminations within the recommended values by IAEA. Future studies will also include phantom experiments to validate the simulation results.

Application of adjoint Monte Carlo to accelerate simulations of mono-directional beams in treatment planning for Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

Nievaart, V. A.; Legrady, D.; Moss, R. L.; Kloosterman, J. L.; Hagen, T. H. J. J. van der; Dam, H. van

2007-01-01

This paper deals with the application of the adjoint transport theory in order to optimize Monte Carlo based radiotherapy treatment planning. The technique is applied to Boron Neutron Capture Therapy where most often mixed beams of neutrons and gammas are involved. In normal forward Monte Carlo simulations the particles start at a source and lose energy as they travel towards the region of interest, i.e., the designated point of detection. Conversely, with adjoint Monte Carlo simulations, the so-called adjoint particles start at the region of interest and gain energy as they travel towards the source where they are detected. In this respect, the particles travel backwards and the real source and real detector become the adjoint detector and adjoint source, respectively. At the adjoint detector, an adjoint function is obtained with which numerically the same result, e.g., dose or flux in the tumor, can be derived as with forward Monte Carlo. In many cases, the adjoint method is more efficient and by that is much quicker when, for example, the response in the tumor or organ at risk for many locations and orientations of the treatment beam around the patient is required. However, a problem occurs when the treatment beam is mono-directional as the probability of detecting adjoint Monte Carlo particles traversing the beam exit (detector plane in adjoint mode) in the negative direction of the incident beam is zero. This problem is addressed here and solved first with the use of next event estimators and second with the application of a Legendre expansion technique of the angular adjoint function. In the first approach, adjoint particles are tracked deterministically through a tube to a (adjoint) point detector far away from the geometric model. The adjoint particles will traverse the disk shaped entrance of this tube (the beam exit in the actual geometry) perpendicularly. This method is slow whenever many events are involved that are not contributing to the point

Boron removal from geothermal waters by electrocoagulation

Energy Technology Data Exchange (ETDEWEB)

Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey)], E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey); Yilmaz, M. Tolga; Paluluoglu, Cihan [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey)

2008-05-01

Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm{sup 2}, but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%.

Boron removal from geothermal waters by electrocoagulation

International Nuclear Information System (INIS)

Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar; Yilmaz, M. Tolga; Paluluoglu, Cihan

2008-01-01

Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm 2 , but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%

Pilot clinical study of boron neutron capture therapy for recurrent hepatic cancer involving the intra-arterial injection of a 10BSH-containing WOW emulsion

International Nuclear Information System (INIS)

Yanagie, Hironobu; Higashi, Syushi; Seguchi, Koji; Ikushima, Ichiro; Fujihara, Mituteru; Nonaka, Yasumasa; Oyama, Kazuyuki; Maruyama, Syoji; Hatae, Ryo; Suzuki, Minoru; Masunaga, Shin-ichiro; Kinashi, Tomoko; Sakurai, Yoshinori; Tanaka, Hiroki; Kondo, Natsuko; Narabayashi, Masaru; Kajiyama, Tetsuya; Maruhashi, Akira; Ono, Koji; Nakajima, Jun

2014-01-01

A 63-year-old man with multiple HCC in his left liver lobe was enrolled as the first patient in a pilot study of boron neutron capture therapy (BNCT) involving the selective intra-arterial infusion of a 10 BSH-containing water-in-oil-in-water emulsion ( 10 BSH-WOW). The size of the tumorous region remained stable during the 3 months after the BNCT. No adverse effects of the BNCT were observed. The present results show that 10 BSH-WOW can be used as novel intra-arterial boron carriers during BNCT for HCC. - Highlights: • We started the pilot clinical study of BNCT to recurrence hepatic cancer. • The tumor size was remained stable during 3 months after BNCT(SD). • No adverse effect as a result of BNCT was observed during follow-up period. • 10 B-containing WOW emulsion can be applied as a novel intra-arterial boron carrier for BNCT for HCC

Iron solubility in highly boron-doped silicon

International Nuclear Information System (INIS)

McHugo, S.A.; McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Weber, E.R.

1998-01-01

We have directly measured the solubility of iron in high and low boron-doped silicon using instrumental neutron activation analysis. Iron solubilities were measured at 800, 900, 1000, and 1100thinsp degree C in silicon doped with either 1.5x10 19 or 6.5x10 14 thinspboronthinspatoms/cm 3 . We have measured a greater iron solubility in high boron-doped silicon as compared to low boron-doped silicon, however, the degree of enhancement is lower than anticipated at temperatures >800thinsp degree C. The decreased enhancement is explained by a shift in the iron donor energy level towards the valence band at elevated temperatures. Based on this data, we have calculated the position of the iron donor level in the silicon band gap at elevated temperatures. We incorporate the iron energy level shift in calculations of iron solubility in silicon over a wide range of temperatures and boron-doping levels, providing a means to accurately predict iron segregation between high and low boron-doped silicon. copyright 1998 American Institute of Physics

Beam Angular Divergence Effects in Ion Implantation

International Nuclear Information System (INIS)

Horsky, T. N.; Hahto, S. K.; Bilbrough, D. G.; Jacobson, D. C.; Krull, W. A.; Goldberg, R. D.; Current, M. I.; Hamamoto, N.; Umisedo, S.

2008-01-01

An important difference between monomer ion beams and heavy molecular beams is a significant reduction in beam angular divergence and increased on-wafer angular accuracy for molecular beams. This advantage in beam quality stems from a reduction in space-charge effects within the beam. Such improved angular accuracy has been shown to have a significant impact on the quality and yield of transistor devices [1,12]. In this study, B 18 H x + beam current and angular divergence data collected on a hybrid scanned beam line that magnetically scans the beam across the wafer is presented. Angular divergence is kept below 0.5 deg from an effective boron energy of 200 eV to 3000 eV. Under these conditions, the beam current is shown analytically to be limited by space charge below about 1 keV, but by the matching of the beam emittance to the acceptance of the beam line above 1 keV. In addition, results of a beam transport model which includes variable space charge compensation are presented, in which a drift mode B 18 H x + beam is compared to an otherwise identical boron beam after deceleration. Deceleration is shown to introduce significant space-charge blow up resulting in a large on-wafer angular divergence. The divergence effects introduced by wafer charging are also discussed.

Improved tribological behavior of boron implanted Ti-6Al-4V

International Nuclear Information System (INIS)

Baker, N.P.; Walter, K.C.; Nastasi, M.

1998-03-01

Boron implanted of Ti6Al4V has been conducted at combinations of 32 and 40 keV to supplement that done previously at 75 keV. Shallower boron depth profiles with higher B-concentrations in the Ti64 surface have been obtained by tailoring the combinations of ion energy and dose. This work used three different ion energy and dose combinations of 4 x 10 17 B-at/cm 2 at 40 keV plus 2 x 10 17 B-at/cm 2 at 32 keV, 4 x 10 17 B-at/cm 2 at 40 keV, and 4 x 10 17 B-at/cm 2 at 32 keV plus 2 x 10 17 B-at/cm 2 at 40 keV. Comparisons are made between Ti6Al4V with a shallow implanted boron depth profile, Ti6Al4V with a deeper boron depth profile and nitrogen implanted using a plasma source ion implantation process. It has been previously shown that while boron implanted Ti64 has a ∼ 30% higher surface hardness than nitrogen implanted Ti64, the N-implantation reduced the wear coefficient of Ti64 by 25--120x, while B-implantation reduced the wear coefficient by 6.5x or less. The results show that no significant improvement is made in the wear resistance of boron implanted Ti6Al4V by increasing the concentration of boron at the surface from approximately 10% to 43%. Transmission electron microscopy (TEM) and selected area diffraction (SAD) indicated the formation of crystalline TiB in the implanted surface layer. Shallower depth profiles result in reductions of the Ti6Al4V wear coefficient by 6.5x or less which is the same result obtained earlier with the deeper boron depth profile. Surface hardness of Ti6Al4V with shallower boron depth profiles was improved approximately 10% compared to the results previously acquired with deeper boron depth profiles

Bulk-boronized limiter operation in the Wendelstein 7-AS stellarator

Energy Technology Data Exchange (ETDEWEB)

Brakel, R; Burhenn, R; Behrisch, R; Grigull, P; Hacker, H; Hildebrandt, D; Hofmann, J V; Mahn, C; Roth, J; Schneider, U; Weller, A [Max-Planck-Inst. fuer Plasmaphysik, Garching (Germany); Hirooka, Y [Inst. of Plasma Physics and Fusion Research, Univ. California, Los Angeles, CA (United States); W7-AS Team; NI Group; ECRH Group

1992-12-01

Bulk-boronized graphite (20% boron) has been tested as a limiter material in the Wendelstein 7-AS stellarator. The recycling behaviour and the plasma impurities are compared for the new material and the formerly used TiC-coated graphite with stainless steel and boronized walls. After conditioning the recycling and the oxygen and carbon levels are comparable for both materials. No significant impact of sputter boronization from the limiters on the oxygen level was observed. A drastical reduction of oxygen by about a factor of 10 was obtained only after additional gas boronization. In this case Z[sub eff] is primarily determined by carbon and boron. For ECF standard discharges Z[sub eff][approx equal]2 with P[sub rad]=6% of the input power was found as compared to Z[sub eff]< or approx.3 and P[sub rad]=10% before boronization and Z[sub eff][approx equal]4, P[sub rad]=20% with TiC-limiters. (orig.).

Fine-tuning the nucleophilic reactivities of boron ate complexes derived from aryl and heteroaryl boronic esters.

Science.gov (United States)

Berionni, Guillaume; Leonov, Artem I; Mayer, Peter; Ofial, Armin R; Mayr, Herbert

2015-02-23

Boron ate complexes derived from thienyl and furyl boronic esters and aryllithium compounds have been isolated and characterized by X-ray crystallography. Products and mechanisms of their reactions with carbenium and iminium ions have been analyzed. Kinetics of these reactions were monitored by UV/Vis spectroscopy, and the influence of the aryl substituents, the diol ligands (pinacol, ethylene glycol, neopentyl glycol, catechol), and the counterions on the nucleophilic reactivity of the boron ate complexes were examined. A Hammett correlation confirmed the polar nature of their reactions with benzhydrylium ions, and the correlation lg k(20 °C)=sN (E+N) was employed to determine the nucleophilicities of the boron ate complexes and to compare them with those of other borates and boronates. The neopentyl and ethylene glycol derivatives were found to be 10(4) times more reactive than the pinacol and catechol derivatives. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative neutron capture radiography for studying the biodistribution of tumor-seeking boron-containing compounds

International Nuclear Information System (INIS)

Gabel, D.; Holstein, H.; Larsson, B.; Gille, L.; Ericson, G.; Sacker, D.; Som, P.; Fairchild, R.G.

1987-01-01

Biodistribution of two compounds presently considered for use in neutron capture therapy has been studied in mice carrying a transplantable Harding-Passey melanoma. A method is described by which quantitative assessment can be made of the boron distribution in whole-body sections of such animals. An alpha-particle-sensitive film is placed in close contact with a freeze-dried section of an animal and exposed to neutrons. The tracks visible after etching are analyzed optoelectronically in fields of 0.6 X 0.6 mm2 and compared to standards of boron homogeneously distributed in liver homogenates. The dynamic range of this method is about two orders of magnitude in concentration, with a lower detection limit of 0.1 to 0.01 ppm 10 B, depending on the rate of induction of spurious tracks by fast neutrons present in the neutron beam chosen. In a transplantable Harding-Passey melanoma in mice, it was found that the sulfhydryl boron hydride Na2B12H11SH presently used for therapy of glioblastoma clears blood, muscle, and brain very rapidly. Its accumulation in tumors was persistent for more than three days. A higher tumor accumulation was observed with its disulfide, which has been suggested for neutron capture therapy. For both compounds, a marked heterogeneity of boron distribution within one tumor was found

Study on boron-film thermal neutron converter prepared by pulsed laser deposition

International Nuclear Information System (INIS)

Song Zifeng; Ye Shuzhen; Chen Ziyu; Song Liao; Shen Ji

2011-01-01

The boron film converter used in the position-sensitive thermal neutron detector is discussed and the method of preparing this converter layer via Pulsed Laser Deposition (PLD) is introduced. The morphology and the composition were studied by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). Both boron and boride existed on the layer surface. It was shown that the energy intensity of laser beam and the substrate temperature both had an important influence on the surface morphology of the film.

Study on boron-film thermal neutron converter prepared by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Song Zifeng; Ye Shuzhen; Chen Ziyu; Song Liao [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China); Shen Ji, E-mail: shenji@ustc.edu.c [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China)

2011-02-15

The boron film converter used in the position-sensitive thermal neutron detector is discussed and the method of preparing this converter layer via Pulsed Laser Deposition (PLD) is introduced. The morphology and the composition were studied by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). Both boron and boride existed on the layer surface. It was shown that the energy intensity of laser beam and the substrate temperature both had an important influence on the surface morphology of the film.

Boronization on NSTX using Deuterated Trimethylboron

International Nuclear Information System (INIS)

Blanchard, W.R.; Gernhardt, R.C.; Kugel, H.W.; LaMarche, P.H.

2002-01-01

Boronization on the National Spherical Torus Experiment (NSTX) has proved to be quite beneficial with increases in confinement and density, and decreases in impurities observed in the plasma. The boron has been applied to the interior surfaces of NSTX, about every 2 to 3 weeks of plasma operation, by producing a glow discharge in the vacuum vessel using deuterated trimethylboron (TMB) in a 10% mixture with helium. Special NSTX requirements restricted the selection of the candidate boronization method to the use of deuterated boron compounds. Deuterated TMB met these requirements, but is a hazardous gas and special care in the execution of the boronization process is required. This paper describes the existing GDC, Gas Injection, and Torus Vacuum Pumping System hardware used for this process, the glow discharge process, and the automated control system that allows for remote operation to maximize both the safety and efficacy of applying the boron coating. The administrative requirements and the detailed procedure for the setup, operation and shutdown of the process are also described

Medical and biological requirements for boron neutron capture therapy

International Nuclear Information System (INIS)

Gahbauer, R.; Goodman, J.H.; Kanellitsas, C.; Clendenon, N.; Blue, J.

1986-01-01

In conventional radiation therapy, tumor doses applied to most solid tumors are limited by the tolerance of normal tissues. The promise of Boron Neutron Capture Therapy lies in its potential to deposit high doses of radiation very specifically to tumor tissue. Theoretically ratios of tumor to normal tissue doses can be achieved significantly higher than conventional radiotherapeutic techniques would allow. Effective dose distributions obtainable are a complex function of the neutron beam characteristics and the macro and micro distributions of boron in tumor and normal tissues. Effective RBE doses are calculated in tumors and normal tissue for thermal, epithermal and 2 keV neutrons

Boron Removal in Seawater Reverse Osmosis System

KAUST Repository

Rahmawati, Karina

2011-07-01

Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

Continued biological investigations of boron-rich oligomeric phosphate diesters (OPDs). Tumor-selective boron agents for BNCT

International Nuclear Information System (INIS)

Lee, Mark W.; Shelly, Kenneth; Kane, Robert R.; Hawthorne, M. Frederick

2006-01-01

Clinical success of Boron Neutron Capture Therapy will rely on the selective intracellular delivery of high concentrations of boron-10 to tumor tissue. In order for a boron agent to facilitate clinical success, the simultaneous needs of obtaining a high tumor dose, high tumor selectivity, and low systemic toxicity must be realized. Boron-rich oligomeric phosphate diesters (OPDs) are a class of highly water-soluble compounds containing up to 40% boron by weight. Previous work in our groups demonstrated that once placed in the cytoplasm of tumor cells, OPDs quickly accumulate within the cell nucleus. The objective of the current study was to determine the biodistribution of seven different free OPDs in BALB/c mice bearing EMT6 tumors. Fructose solutions containing between 1.4 and 6.4 micrograms of boron per gram of tissue were interveinously injected in mice seven to ten days after tumor implantation. At intervals during the study, animals were euthanized and samples of tumor, blood, liver, kidney, brain and skin were collected and analyzed for boron content using ICP-AES. Tumor boron concentrations of between 5 and 29 ppm were achieved and maintained over the 72-hour time course of each experiment. Several OPDs demonstrated high tumor selectivity with one oligomer exhibiting a tumor to blood ratio of 35:1. The apparent toxicity of each oligomer was assessed through animal behavior during the experiment and necropsy of each animal upon sacrifice. (author)

A colorimetric determination of boron in biological sample for boron neutron capture therapy (BNCT)

International Nuclear Information System (INIS)

Camillo, M.A.P.; Tomac Junior, U.

1990-01-01

The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of glyemas and gluoblastomas grade III and IV than other therapies. During the treatment the levels of Na 2 10 B 12 H 11 SH must be known in several compartiments of the organism and with this purpose the method of colorimetric determination of boron using curcumine was established. This method is simple, reprodutible and adequate sensitivity for this control. (author) [pt

A colorimetric determination of boron in biological sample for boron neutron capture therapy

International Nuclear Information System (INIS)

Camilo, M.A.P.; Tomac Junior, U.

1989-01-01

The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of gliomas and glioblastomas grade III and IV than other therapies. During the treatment of levels of Na 2 10 B 12 H 11 S H must be known in several compartments of the organism and with this purpose the method of colorimetric determination of boron using curcumin was established. This method is simples, reproducible and has adequate sensitivity for this control. (author). 7 refs, 3 figs, 1 tab

Commercial Clinical Application of Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

1999-01-01

CRADA No. 95-CR-09 among the LITCO--now Bechtel BWXT Idaho, LLC; a private company, Neutron Therapies Limited Liability Company, NTL formerly Ionix Corporation; and Washington State University was established in 1996 to further the development of BNCT. NTL has established a laboratory for the synthesis, under US FDA approved current Good Manufacturing Practices (cGMP) guidelines, of key boron intermediates and final boron agents for BNCT. The company has focused initially on the development of the compound GB-10 (Na 2 B 10 H 10 ) as the first boron agent of interest. An Investigational New Drug (IND) application for GB-10 has been filed and approved by the FDA for a Phase I human biodistribution trial in patients with non-small cell lung cancer and glioblastoma multiforme at UW under the direction of Professor Keith Stelzer, Principal Investigator (PI). These trials are funded by NTL under a contract with the UW, Department of Radiation Oncology, and the initial phases are nearing completion. Initial results show that boron-10 concentrations on the order of 100 micrograms per gram (100 ppm) can be achieved and maintained in blood with no indication of toxicity

Boron-containing thioureas for neutron capture therapy. Borhaltige Thioharnstoffe fuer die Neutroneneinfangtherapie

Energy Technology Data Exchange (ETDEWEB)

Ketz, H.

1993-10-21

Melanin is produced in large amounts in malignant melanotic melanomas. Because thiourea compounds are covalently incorporated into melanin during its biosynthesis, the preparation of boronated thiourea-derivatives is of particular interest for the BNCT (Boron Neutron Capture Therapy). Accumulation of boron in tumors by means of boronated thiourea-derivatives may therefore provide levels of [sup 10]B which are useful for BNCT. In BNCT the tumor containing the boron compound is irradiated with epithermal neutrons to generate He- and Li-nuclei from the [sup 10]B which can then destroy the tumor cells. Because of the short ranges of these particles (approximately one cell diameter) the damage will be almost exclusively confined to the tumor leaving normal tissue unharmed. High accumulation of 2-mercapto-1-methylimidazole (methimazole) in melanotic melanomas has been described in the literature. Boronated derivatives of methimazole were therefore synthesized. Boron was in the form of a boronic acid, a nido-carbonate and a mercaptoundeca hydro-closo-dodecaborate (BSH). The synthesis of the boron cluster derivatives of methimazole (nido-carborate- and BSH-derivatives) with 9 resp. 12 boron atoms in the molecule were expected to achieve higher concentrations of boron in the tumor than in the case of the boronic acid compound with its single boron atom. (orig.)

Pilot clinical study of boron neutron capture therapy for recurrent hepatic cancer involving the intra-arterial injection of a (10)BSH-containing WOW emulsion.

Science.gov (United States)

Yanagie, Hironobu; Higashi, Syushi; Seguchi, Koji; Ikushima, Ichiro; Fujihara, Mituteru; Nonaka, Yasumasa; Oyama, Kazuyuki; Maruyama, Syoji; Hatae, Ryo; Suzuki, Minoru; Masunaga, Shin-ichiro; Kinashi, Tomoko; Sakurai, Yoshinori; Tanaka, Hiroki; Kondo, Natsuko; Narabayashi, Masaru; Kajiyama, Tetsuya; Maruhashi, Akira; Ono, Koji; Nakajima, Jun; Ono, Minoru; Takahashi, Hiroyuki; Eriguchi, Masazumi

2014-06-01

A 63-year-old man with multiple HCC in his left liver lobe was enrolled as the first patient in a pilot study of boron neutron capture therapy (BNCT) involving the selective intra-arterial infusion of a (10)BSH-containing water-in-oil-in-water emulsion ((10)BSH-WOW). The size of the tumorous region remained stable during the 3 months after the BNCT. No adverse effects of the BNCT were observed. The present results show that (10)BSH-WOW can be used as novel intra-arterial boron carriers during BNCT for HCC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neutron spectrum for neutron capture therapy in boron

International Nuclear Information System (INIS)

Medina C, D.; Soto B, T. G.; Baltazar R, A.; Vega C, H. R.

2016-10-01

Glioblastoma multiforme is the most common and aggressive of brain tumors and is difficult to treat by surgery, chemotherapy or conventional radiation therapy. One treatment alternative is the Neutron Capture Therapy in Boron, which requires a beam modulated in neutron energy and a drug with 10 B able to be fixed in the tumor. When the patients head is exposed to the neutron beam, they are captured by the 10 B and produce a nucleus of 7 Li and an alpha particle whose energy is deposited in the cancer cells causing it to be destroyed without damaging the normal tissue. One of the problems associated with this therapy is to have an epithermal neutrons flux of the order of 10 9 n/cm 2 -sec, whereby irradiation channels of a nuclear research reactor are used. In this work using Monte Carlo methods, the neutron spectra obtained in the radial irradiation channel of the TRIGA Mark III reactor are calculated when inserting filters whose position and thickness have been modified. From the arrangements studied, we found that the Fe-Cd-Al-Cd polyethylene filter yielded a ratio between thermal and epithermal neutron fluxes of 0.006 that exceeded the recommended value (<0.05), and the dose due to the capture gamma rays is lower than the dose obtained with the other arrangements studied. (Author)

Designing an Epithermal Neutron Beam for Boron Neutron Capture Therapy for the Fusion Reactions 2H(d,n)3He and 3H(d,n)4He1

International Nuclear Information System (INIS)

Verbeke, J.M.; Costes, S.V.; Bleuel, D.; Vujic, J.; Leung, K.N.

1998-01-01

A beam shaping assembly has been designed to moderate high energy neutrons from the fusion reactions 2 H(d,N) 3 He and 3 H(d,n) 4 He for use fin boron neutron capture therapy. The low neutron yield of the 2 H(d,n) 3 He reaction led to unacceptably long treatment times. However, a 160 mA deuteron beam of energy 400 keV led to a treatment time of 120 minutes with the reaction 3 H(d,n) 4 He. Equivalent doses of 9.6 Gy-Eq and 21.9 Gy-Eq to the skin and to a 8 cm deep tumor respectively have been computed

An empirical model for parameters affecting energy consumption in boron removal from boron-containing wastewaters by electrocoagulation

Energy Technology Data Exchange (ETDEWEB)

Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey)]. E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey)

2007-06-01

In this study, it was investigated parameters affecting energy consumption in boron removal from boron containing wastewaters prepared synthetically, via electrocoagulation method. The solution pH, initial boron concentration, dose of supporting electrolyte, current density and temperature of solution were selected as experimental parameters affecting energy consumption. The obtained experimental results showed that boron removal efficiency reached up to 99% under optimum conditions, in which solution pH was 8.0, current density 6.0mA/cm{sup 2}, initial boron concentration 100mg/L and solution temperature 293K. The current density was an important parameter affecting energy consumption too. High current density applied to electrocoagulation cell increased energy consumption. Increasing solution temperature caused to decrease energy consumption that high temperature decreased potential applied under constant current density. That increasing initial boron concentration and dose of supporting electrolyte caused to increase specific conductivity of solution decreased energy consumption. As a result, it was seen that energy consumption for boron removal via electrocoagulation method could be minimized at optimum conditions. An empirical model was predicted by statistically. Experimentally obtained values were fitted with values predicted from empirical model being as following;[ECB]=7.6x10{sup 6}x[OH]{sup 0.11}x[CD]{sup 0.62}x[IBC]{sup -0.57}x[DSE]{sup -0.}= {sup 04}x[T]{sup -2.98}x[t] Unfortunately, the conditions obtained for optimum boron removal were not the conditions obtained for minimum energy consumption. It was determined that support electrolyte must be used for increase boron removal and decrease electrical energy consumption.

An empirical model for parameters affecting energy consumption in boron removal from boron-containing wastewaters by electrocoagulation

International Nuclear Information System (INIS)

Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar

2007-01-01

In this study, it was investigated parameters affecting energy consumption in boron removal from boron containing wastewaters prepared synthetically, via electrocoagulation method. The solution pH, initial boron concentration, dose of supporting electrolyte, current density and temperature of solution were selected as experimental parameters affecting energy consumption. The obtained experimental results showed that boron removal efficiency reached up to 99% under optimum conditions, in which solution pH was 8.0, current density 6.0mA/cm 2 , initial boron concentration 100mg/L and solution temperature 293K. The current density was an important parameter affecting energy consumption too. High current density applied to electrocoagulation cell increased energy consumption. Increasing solution temperature caused to decrease energy consumption that high temperature decreased potential applied under constant current density. That increasing initial boron concentration and dose of supporting electrolyte caused to increase specific conductivity of solution decreased energy consumption. As a result, it was seen that energy consumption for boron removal via electrocoagulation method could be minimized at optimum conditions. An empirical model was predicted by statistically. Experimentally obtained values were fitted with values predicted from empirical model being as following;[ECB]=7.6x10 6 x[OH] 0.11 x[CD] 0.62 x[IBC] -0.57 x[DSE] -0.04 x[T] -2.98 x[t] Unfortunately, the conditions obtained for optimum boron removal were not the conditions obtained for minimum energy consumption. It was determined that support electrolyte must be used for increase boron removal and decrease electrical energy consumption.

Toward deep blue nano hope diamonds: heavily boron-doped diamond nanoparticles.

Science.gov (United States)

Heyer, Steffen; Janssen, Wiebke; Turner, Stuart; Lu, Ying-Gang; Yeap, Weng Siang; Verbeeck, Jo; Haenen, Ken; Krueger, Anke

2014-06-24

The production of boron-doped diamond nanoparticles enables the application of this material for a broad range of fields, such as electrochemistry, thermal management, and fundamental superconductivity research. Here we present the production of highly boron-doped diamond nanoparticles using boron-doped CVD diamond films as a starting material. In a multistep milling process followed by purification and surface oxidation we obtained diamond nanoparticles of 10-60 nm with a boron content of approximately 2.3 × 10(21) cm(-3). Aberration-corrected HRTEM reveals the presence of defects within individual diamond grains, as well as a very thin nondiamond carbon layer at the particle surface. The boron K-edge electron energy-loss near-edge fine structure demonstrates that the B atoms are tetrahedrally embedded into the diamond lattice. The boron-doped diamond nanoparticles have been used to nucleate growth of a boron-doped diamond film by CVD that does not contain an insulating seeding layer.

Ion beam studies

International Nuclear Information System (INIS)

Freeman, J.H.; Chivers, D.J.; Gard, G.A.; Temple, W.

1977-04-01

A description of techniques for the production of intense beams of heavy ions is given. A table of recommended operational procedures for most elements is included. The ionisation of boron is considered in some detail because of its particular importance as a dopant for ion implantation. (author)

Study of a neutron producing target via the 7Li(p,n)7Be reaction near its energy threshold for BNCT (boron neutron capture therapy)

International Nuclear Information System (INIS)

Burlon, Alejandro; Kreiner, Andres J.; Debray, Mario E.; Stoliar, Pablo; Kesque, Jose M.; Naab, Fabian; Ozafran, Mabel J.; Schuff, Juan; Vazquez, Monica; Caraballo, Maria E.; Valda, Alejandro; Somacal, Hector; Davidson, Miguel; Davidson, Jorge

2000-01-01

In the framework of Accelerator Based BNCT (AB-BNCT) the 7 Li(p,n) 7 Be reaction near its energy threshold is one of the most promising. In this work a thick LiF target irradiated with a proton beam was studied as a neutron source. The 1.88-2.0 MeV proton beam was produced by the tandem accelerator TANDAR at CNEA's facilities in Buenos Aires. A water-filled phantom, containing a boron sample was irradiated with the resulting neutron beam. The boron neutron capture reaction produces a 0.478 MeV gamma ray in 94 % of the cases. The neutron yield was monitored by detecting this gamma ray using a germanium detector with an 'anti-Compton' shield. Moreover, the thermal neutron flux was evaluated at different depths inside the phantom using bare and Cd-covered gold foils. A maximum neutron thermal flux of 1.4 x 10 8 1/(cm 2 -s-mA) was obtained at 4.2 cm from the phantom surface. (author)

Neutron dosimetry in boron neutron capture therapy

International Nuclear Information System (INIS)

Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

1981-01-01

The recent development of various borated compounds and the utilization of one of these (Na 2 B 12 H 11 SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with 10 B in boron containing cells through the 10 B(n,α) 7 Li reaction producing charged particles with a maximum range of approx. 10μm in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize 6 Li and 10 B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the 14 N(n,p) 14 C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils

Isotope engineering of van der Waals interactions in hexagonal boron nitride

Science.gov (United States)

Vuong, T. Q. P.; Liu, S.; van der Lee, A.; Cuscó, R.; Artús, L.; Michel, T.; Valvin, P.; Edgar, J. H.; Cassabois, G.; Gil, B.

2018-02-01

Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes (10B and 11B) compared to those with the natural distribution of boron (20 at% 10B and 80 at% 11B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in 10BN than in 11BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

Application of 1013 ohm Faraday cup current amplifiers for boron isotopic analyses by solution mode and laser ablation multicollector inductively coupled plasma mass spectrometry.

Science.gov (United States)

Lloyd, Nicholas S; Sadekov, Aleksey Yu; Misra, Sambuddha

2018-01-15

Boron isotope ratios (δ 11 B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts. 10 13 ohm amplifier technology has previously been applied to several radiogenic systems, but has thus far not been applied to non-traditional stable isotopes. Here we apply 10 13 ohm amplifier technology for the measurement of boron isotope ratios using solution mode MC-ICP-MS and laser ablation mode (LA-)MC-ICP-MS techniques. Precision is shown for reference materials as well as for low-volume foraminifera samples. The baseline uncertainty for a 0.1 pA 10 B + ion beam is reduced to ohm amplifier technology is demonstrated to offer advantages for the determination of δ 11 B values by both MC-ICP-MS and LA-MC-ICP-MS for small samples of biogenic carbonates, such as foraminifera shells. 10 13 ohm amplifier technology will also be of benefit to other non-traditional stable isotope measurements. Copyright © 2017 John Wiley & Sons, Ltd.

Quantitative evaluation of boron neutron capture therapy (BNCT) drugs for boron delivery and retention at subcellular scale resolution in human glioblastoma cells with imaging secondary ion mass spectrometry (SIMS)

Science.gov (United States)

Chandra, S.; Ahmad, T.; Barth, R. F.; Kabalka, G. W.

2014-01-01

Boron neutron capture therapy (BNCT) of cancer depends on the selective delivery of a sufficient number of boron-10 (10B) atoms to individual tumor cells. Cell killing results from the 10B (n, α)7Li neutron capture and fission reactions that occur if a sufficient number of 10B atoms are localized in the tumor cells. Intranuclear 10B localization enhances the efficiency of cell killing via damage to the DNA. The net cellular content of 10B atoms reflects both bound and free pools of boron in individual tumor cells. The assessment of these pools, delivered by a boron delivery agent, currently cannot be made at subcellular scale resolution by clinically applicable techniques such as PET and MRI. In this study, secondary ion mass spectrometry (SIMS) based imaging instrument, a CAMECA IMS 3f ion microscope, capable of 500 nm spatial resolution was employed. Cryogenically prepared cultured human T98G glioblastoma cells were evaluated for boron uptake and retention of two delivery agents. The first, L-p-boronophenylalanine (BPA), has been used clinically for BNCT of high grade gliomas, recurrent tumors of the head and neck region and melanomas. The second, a boron analogue of an unnatural amino acid, 1-amino-3-borono-cyclopentanecarboxylic acid (cis-ABCPC), has been studied in rodent glioma and melanoma models by quantification of boron in the nucleus and cytoplasm of individual tumor cells. The bound and free pools of boron were assessed by exposure of cells to boron-free nutrient medium. Both BPA and cis-ABCPC delivered almost 70% of the pool of boron in the free or loosely bound form to the nucleus and cytoplasm of human glioblastoma cells. This free pool of boron could be easily mobilized out of the cell and was in some sort of equilibrium with extracellular boron. In the case of BPA, the intracellular free pool of boron also was affected by the presence of phenylalanine in the nutrient medium. This suggests that it might be advantageous if patients were placed on a

Irradiation Effects in Fortiweld Steel Containing Different Boron Isotopes

International Nuclear Information System (INIS)

Grounes, M.

1967-07-01

Tensile specimens and miniature impact specimens of the low alloyed pressure vessel steel Fortiweld have been irradiated at 265 deg C in R2 to two neutron doses, 6.5 x 10 18 n/cm 2 (> 1 MeV) and 4 x 10 19 n/cm 2 (thermal) and also 9.0 x 10 18 n/cm 2 (> 1 MeV) and 6 x 10 19 n/cm 2 (thermal). Material from three laboratory melts, in which the boron consisted of 10 B, 11 B and natural boron respectively, were investigated. The results both of tensile tests and impact tests with miniature impact specimens show that the 10 B-alloyed material was changed more and the 11 B-alloyed material was changed less than the material containing natural boron. At the higher neutron dose the increase in yield strength (0.2 % offset yield strength) was 11 kg/mm in the 10 B containing material compared to 5 kg/mm in the 11 B-containing material. The decrease in total elongation was 5 and 0 percentage units respectively. The transition temperature was increased 190 deg C at the higher neutron dose in the 10 B-alloyed material, 40 deg C in the 11 B-alloyed material and 80 deg C in the material containing natural boron

Boronated monoclonal antibody conjugates for neutron capture therapy

International Nuclear Information System (INIS)

Borg, D.C.; Elmore, J.J. Jr.; Ferrone, S.

1986-01-01

This paper describes the effectiveness of 10 B-labeled monoclonal antibodies against Colo-38 human melanoma in vitro. The authors obtained high boron to antibody ratios while maintaining antibody activity by using dextran intermediate carriers to link 10 B to the antibody. They developed a double cell quasi-competitive binding bioassay to minimize the effects of nonspecific binding of boronated complexes to cells. 1 fig., 2 tabs

Possible alternation of the blood-brain barrier by boron-neutron capture therapy

International Nuclear Information System (INIS)

Hatanaka, H.; Moritani, M.; Camillo, M.

1991-01-01

In the course of re-assessment of boron-neutron capture therapy (BNCT) for malignant brain tumors, fractionation of neutron irradiation has been proposed. The authors have used BNCT with a single fraction technique during the past 21 years and now decided to study some effects of fractionation. Twenty-two healthy mouse brains were irradiated with thermal neutrons after boron-10 injection (mercaptoundecahydrododecaborate). A second dose of boron-10 was administered and its uptake in the boron-neutron-capture-irradiated brains was determined. A tendency towards increased boron uptake in the moderately BNCT-treated brains was noticed, which may result in increased brain damage if fractionated neutron irradiation is used. (orig.)

A large animal model for boron neutron capture therapy

International Nuclear Information System (INIS)

Gavin, P.R.; Kraft, S.L.; DeHaan, C.E.; Moore, M.P.; Griebenow, M.L.

1992-01-01

An epithermal neutron beam is needed to treat relatively deep seated tumors. The scattering characteristics of neutrons in this energy range dictate that in vivo experiments be conducted in a large animal to prevent unacceptable total body irradiation. The canine species has proven an excellent model to evaluate the various problems of boron neutron capture utilizing an epithermal neutron beam. This paper discusses three major components of the authors study: (1) the pharmacokinetics of borocaptate sodium (NA 2 B 12 H 11 SH or BSH) in dogs with spontaneously occurring brain tumors, (2) the radiation tolerance of normal tissues in the dog using an epithermal beam alone and in combination with borocaptate sodium, and (3) initial treatment of dogs with spontaneously occurring brain tumors utilizing borocaptate sodium and an epithermal neutron beam

Coupling of dextrans conjugated with boron to gamma globulin: a model for NCT

International Nuclear Information System (INIS)

Elmore, J.J. Jr.; Borg, D.C.; Micca, P.; Gabel, D.

1983-01-01

Our project is to meet more effectively the well known primary requirement for treatment with boron-10 neutron capture therapy (NCT): namely, the selective localization of a sufficient amount of boron in or on target cells. Monoclonal antibodies (MCA) to tumor-associated antigens are attractive targeting carriers for boron-10 in terms of the needed selective localization. However the densities of surface receptors on tumor cells have seemed deficient to achieve successful NCT. If one seeks the necessary radiotherapeutic ratios by increasing the numbers of boron atoms or carborane cages bound per MCA, then inactivation of the antibody can occur through loss of receptor specificity and/or by precipitation of the protein. To achieve the goal of overcoming the limitations of antibody binding capacity, we have elected to use water-soluble dextrans as intermediate carriers. This permits each MCA molecule to target many atoms of boron-10 to the specified antigenic receptors while only 5 to 10 of the amino acid residues of the protein are conjugated by dextrans carrying boron-10

Boron tolerance in NS wheat lines

Directory of Open Access Journals (Sweden)

Brdar Milka

2006-01-01

Full Text Available Boron is an essential micronutrient for higher plants. Present in excessive amounts boron becomes toxic and can limit plant growth and yield. Suppression of root growth is one of the symptoms of boron toxicity in wheat. This study was undertaken to investigate the response of 10 perspective NS lines of wheat to high concentrations of boron. Analysis of root growth was done on young plants, germinated and grown in the presence of different concentrations of boric acid (0, 50,100 and 150 mg/1. Significant differences occurred between analyzed genotypes and treatments regarding root length. Average suppression of root growth was between 11,6 and 34,2%, for line NS 252/02 are even noted 61,4% longer roots at treatments in relation to the control. Lines with mean suppression of root growth less than 20% (NS 101/02, NS 138/01, NS 53/03 and NS 73/02 may be considered as boron tolerant. Spearmans coefficients showed high level of agreement regarding rang of root length for genotypes treated with 100 and 150 mg H3BO3/l.

Enhanced therapeutic effect on murine melanoma and angiosarcoma cells by boron neutron capture therapy using a boronated metalloporphyrin

International Nuclear Information System (INIS)

Yamada, Yoshihiko; Ichihashi, Masamitsu; Kahl, S.B.; Toda, Ken-ichi.

1994-01-01

We have already achieved successful treatment of several human patients with malignant melanoma by boron neutron capture therapy (BNCT) using 10 B 1 -paraboronophenylalanine ( 10 B 1 -BPA·HCl). In this study we used a new compound, a manganese boronated protoporphyrin (Mn- 10 BOPP), and compared it to 10 B 1 -BPA·HCl with respect to uptake in murine melanoma and angiosarcoma cells as well as to their cell killing effect. 10 B uptake was measured in a new method, and the new compound was much more incorporated into both cells than 10 B 1 -BPA·HCl. Furthermore, melanoma and angiosarcoma cells preincubated with the new compound were 15 to 20 times more efficiently killed by BNCT than cells preincubated with 10 B 1 -BPA·HCl. (author)

In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

CERN Document Server

Yamamoto, T; Horiguchi, Y; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Yamamoto, K

2002-01-01

The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without sup 1 sup 0 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of sup 1 sup 0 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99+-0.24, 3.04+-0.19 and 1.43+-0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50+-0.32, 2.34+-0.30 and 2.17+-0.28 for EN...

Boron atom reactions

International Nuclear Information System (INIS)

Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

1982-01-01

The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

In-beam test of the Boron-10 Multi-Grid neutron detector at the IN6 time-of-flight spectrometer at the ILL

Energy Technology Data Exchange (ETDEWEB)

Birch, J; Hultman, L; Höglund, C [Linköping University, Thin Film Physics Division, IFM, SE-581 83 Linköping (Sweden); Buffet, J-C; Clergeau, J-F; Correa, J; Van Esch, P; Ferraton, M; Guerard, B; Halbwachs, J; Khaplanov, A; Koza, M; Piscitelli, F; Zbiri, M [Institute Laue Langevin, Rue Jules Horowitz, FR-38000 Grenoble (France); Hall-Wilton, R [European Spallation Source ESS AB, P.O Box 176, SE-221 00 Lund (Sweden)

2014-07-24

A neutron detector concept based on solid layers of boron carbide enriched in {sup 10}B has been in development for the last few years as an alternative for {sup 3}He by collaboration between the ILL, ESS and Linköping University. This Multi-Grid detector uses layers of aluminum substrates coated with {sup 10}B{sub 4}C on both sides that are traversed by the incoming neutrons. Detection is achieved using a gas counter readout principle. By segmenting the substrate and using multiple anode wires, the detector is made inherently position sensitive. This development is aimed primarily at neutron scattering instruments with large detector areas, such as time-of-flight chopper spectrometers. The most recent prototype has been built to be interchangeable with the {sup 3}He detectors of IN6 at ILL. The {sup 10}B detector has an active area of 32 x 48cm{sup 2}. It was installed at the IN6 instrument and operated for several weeks, collecting data in parallel with the regularly scheduled experiments, thus providing the first side-by-side comparison with the conventional {sup 3}He detectors. Results include an efficiency comparison, assessment of the in-detector scattering contribution, sensitivity to gamma-rays and the signal-to-noise ratio in time-of-flight spectra. The good expected performance has been confirmed with the exception of an unexpected background count rate. This has been identified as natural alpha activity in aluminum. New convertor substrates are under study to eliminate this source of background.

Standard specification for boron-Based neutron absorbing material systems for use in nuclear spent fuel storage racks

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This specification defines criteria for boron-based neutron absorbing material systems used in racks in a pool environment for storage of nuclear light water reactor (LWR) spent-fuel assemblies or disassembled components to maintain sub-criticality in the storage rack system. 1.2 Boron-based neutron absorbing material systems normally consist of metallic boron or a chemical compound containing boron (for example, boron carbide, B4C) supported by a matrix of aluminum, steel, or other materials. 1.3 In a boron-based absorber, neutron absorption occurs primarily by the boron-10 isotope that is present in natural boron to the extent of 18.3 ± 0.2 % by weight (depending upon the geological origin of the boron). Boron, enriched in boron-10 could also be used. 1.4 The materials systems described herein shall be functional – that is always be capable to maintain a B10 areal density such that subcriticality Keff <0.95 or Keff <0.98 or Keff < 1.0 depending on the design specification for the service...

Folate Functionalized Boron Nitride Nanotubes and their Selective Uptake by Glioblastoma Multiforme Cells: Implications for their Use as Boron Carriers in Clinical Boron Neutron Capture Therapy.

Science.gov (United States)

Ciofani, Gianni; Raffa, Vittoria; Menciassi, Arianna; Cuschieri, Alfred

2008-11-25

Boron neutron capture therapy (BNCT) is increasingly being used in the treatment of several aggressive cancers, including cerebral glioblastoma multiforme. The main requirement for this therapy is selective targeting of tumor cells by sufficient quantities of (10)B atoms required for their capture/irradiation with low-energy thermal neutrons. The low content of boron targeting species in glioblastoma multiforme accounts for the difficulty in selective targeting of this very malignant cerebral tumor by this radiation modality. In the present study, we have used for the first time boron nitride nanotubes as carriers of boron atoms to overcome this problem and enhance the selective targeting and ablative efficacy of BNCT for these tumors. Following their dispersion in aqueous solution by noncovalent coating with biocompatible poly-l-lysine solutions, boron nitride nanotubes were functionalized with a fluorescent probe (quantum dots) to enable their tracking and with folic acid as selective tumor targeting ligand. Initial in vitro studies have confirmed substantive and selective uptake of these nanovectors by glioblastoma multiforme cells, an observation which confirms their potential clinical application for BNCT therapy for these malignant cerebral tumors.

Folate Functionalized Boron Nitride Nanotubes and their Selective Uptake by Glioblastoma Multiforme Cells: Implications for their Use as Boron Carriers in Clinical Boron Neutron Capture Therapy

Directory of Open Access Journals (Sweden)

Ciofani Gianni

2008-01-01

Full Text Available Abstract Boron neutron capture therapy (BNCT is increasingly being used in the treatment of several aggressive cancers, including cerebral glioblastoma multiforme. The main requirement for this therapy is selective targeting of tumor cells by sufficient quantities of10B atoms required for their capture/irradiation with low-energy thermal neutrons. The low content of boron targeting species in glioblastoma multiforme accounts for the difficulty in selective targeting of this very malignant cerebral tumor by this radiation modality. In the present study, we have used for the first time boron nitride nanotubes as carriers of boron atoms to overcome this problem and enhance the selective targeting and ablative efficacy of BNCT for these tumors. Following their dispersion in aqueous solution by noncovalent coating with biocompatible poly-l-lysine solutions, boron nitride nanotubes were functionalized with a fluorescent probe (quantum dots to enable their tracking and with folic acid as selective tumor targeting ligand. Initial in vitro studies have confirmed substantive and selective uptake of these nanovectors by glioblastoma multiforme cells, an observation which confirms their potential clinical application for BNCT therapy for these malignant cerebral tumors.

Discharge cleaning on TFTR after boronization

International Nuclear Information System (INIS)

Mueller, D.; Dylla, H.F.; LaMarche, P.H.; Bell, M.G.; Blanchard, W.; Bush, C.E.; Gentile, C.; Hawryluk, R.J.; HIll, K.W.; Janos, A.C.; Jobes, F.C; Owens, D.K.; Pearson, G.; Schivell, J.; Ulrickson, M.A.; Vannoy, C.; Wong, K.L.

1991-05-01

At the beginning of the 1990 TFTR experimental run, after replacement of POCO-AXF-5Q graphite tiles on the midplane of the bumper limiter by carbon fiber composite (CFC) tiles and prior to any Pulse Discharge Cleaning (PDC), boronization was performed. Boronization is the deposition of a layer of boron and carbon on the vacuum vessel inner surface by a glow discharge in a diborane, methane and helium mixture. The amount of discharge cleaning required after boronization was substantially reduced compared to that which was needed after previous openings when boronization was not done. Previously, after a major shutdown, about 10 5 low current (∼20 kA) Taylor Discharge Cleaning (TDC) pulses were required before high current (∼400 kA) aggressive Pulse Discharge Cleaning (PDC) pulses could be performed successfully. Aggressive PDC is used to heat the limiters from the vessel bakeout temperature of 150 degrees C to 250 degrees C for a period of several hours. Heating the limiters is important to increase the rate at which water is removed from the carbon limiter tiles. After boronization, the number of required TDC pulses was reduced to <5000. The number of aggressive PDC pulses required was approximately unchanged. 14 refs., 1 tab

SU-F-T-140: Assessment of the Proton Boron Fusion Reaction for Practical Radiation Therapy Applications Using MCNP6

Energy Technology Data Exchange (ETDEWEB)

Adam, D; Bednarz, B [University of Wisconsin, Madison, WI (United States)

2016-06-15

Purpose: The proton boron fusion reaction is a reaction that describes the creation of three alpha particles as the result of the interaction of a proton incident upon a 11B target. Theoretically, the proton boron fusion reaction is a desirable reaction for radiation therapy applications in that, with the appropriate boron delivery agent, it could potentially combine the localized dose delivery protons exhibit (Bragg peak) and the local deposition of high LET alpha particles in cancerous sites. Previous efforts have shown significant dose enhancement using the proton boron fusion reaction; the overarching purpose of this work is an attempt to validate previous Monte Carlo results of the proton boron fusion reaction. Methods: The proton boron fusion reaction, 11B(p, 3α), is investigated using MCNP6 to assess the viability for potential use in radiation therapy. Simple simulations of a proton pencil beam incident upon both a water phantom and a water phantom with an axial region containing 100ppm boron were modeled using MCNP6 in order to determine the extent of the impact boron had upon the calculated energy deposition. Results: The maximum dose increase calculated was 0.026% for the incident 250 MeV proton beam scenario. The MCNP simulations performed demonstrated that the proton boron fusion reaction rate at clinically relevant boron concentrations was too small in order to have any measurable impact on the absorbed dose. Conclusion: For all MCNP6 simulations conducted, the increase of absorbed dose of a simple water phantom due to the 11B(p, 3α) reaction was found to be inconsequential. In addition, it was determined that there are no good evaluations of the 11B(p, 3α) reaction for use in MCNPX/6 and further work should be conducted in cross section evaluations in order to definitively evaluate the feasibility of the proton boron fusion reaction for use in radiation therapy applications.

Boron, phosphorus, and gallium determination in silicon crystals doped with gallium

International Nuclear Information System (INIS)

Shklyar, B.L.; Dankovskij, Yu.V.; Trubitsyn, Yu.V.

1989-01-01

When studying IR transmission spectra of silicon doped with gallium in the range of concentrations 1 x 10 14 - 5 x 10 16 cm -3 , the possibility to quantity at low (∼ 20 K) temperatures residual impurities of boron and phosphorus is ascertained. The lower determination limit of boron is 1 x 10 12 cm -3 for a sample of 10 nm thick. The level of the impurities in silicon crystals, grown by the Czochralski method and method of crucible-free zone melting, is measured. Values of boron and phosphorus concentrations prior to and after their alloying with gallium are compared

Radiological analysis of plutonium glass batches with natural/enriched boron

International Nuclear Information System (INIS)

Rainisch, R.

2000-01-01

The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use of enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B 2 O 3 . Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will make the handling

Boron complexing with H-resorcinol and acidic hydroxyxanthene dyes

International Nuclear Information System (INIS)

Nazarenko, V.A.; Flyantikova, G.V.; Chekirda, T.N.

1984-01-01

Complex formation of boron with H-resorcinol (hr; 2,4-dihydroxybenzene-azo -8-hydroxynaphtalene-3,6-disulfonic acid) and acidic hydroxyxanthene dyes (hxd: fluorescein, eosine, erathrosine). Mixed-ligand complexes with a ratio of r:hr:hxd=1:1:1 are formed at pH=5-6. The chemism of the complex formation of boron with H-resorcinol and fluorescein has been studied. The stability consta nt of the complex is 1.12x10 21 , the conditional molar absorptivitis 1.80x10 0 . This complex formation reaction was used for photometric determination of boron in natural water

Microhardness of boron, titanium, and nitrogen implanted steel

International Nuclear Information System (INIS)

Sowa, M.; Szyszko, W.; Sielanko, J.; Glusiec, L.

1989-01-01

Mechanically polished steel (1H18N9T) and (15GTM) samples are implanted with boron, titanium, and nitrogen ions, with dose ranging from 10 16 to 10 17 ions/cm 2 . The implantation energy varied from 100 to 250 keV. Implanted samples are heat-treated at 400 to 800 0 C in vacuum. The microhardness of implanted samples is measured by using a Hanneman tester with loads ranging from 2 to 40 g. The influence of annealing temperature on microhardness of the implanted layers is determined. The diffusion of boron from the implanted layers is also investigated by using the secondary ion mass spectrometer. The diffusion coefficients of boron in steel are determined. (author)

Graphite and boron carbide composites made by hot-pressing

International Nuclear Information System (INIS)

Miyazaki, K.; Hagio, T.; Kobayashi, K.

1981-01-01

Composites consisting of graphite and boron carbide were made by hot-pressing mixed powders of coke carbon and boron carbide. The change of relative density, mechanical strength and electrical resistivity of the composites and the X-ray parameters of coke carbon were investigated with increase of boron carbide content and hot-pressing temperature. From these experiments, it was found that boron carbide powder has a remarkable effect on sintering and graphitization of coke carbon powder above the hot-pressing temperature of 2000 0 C. At 2200 0 C, electrical resistivity of the composite and d(002) spacing of coke carbon once showed minimum values at about 5 to 10 wt% boron carbide and then increased. The strength of the composite increased with increase of boron carbide content. It was considered that some boron from boron carbide began to diffuse substitutionally into the graphite structure above 2000 0 C and densification and graphitization were promoted with the diffusion of boron. Improvements could be made to the mechanical strength, density, oxidation resistance and manufacturing methods by comparing with the properties and processes of conventional graphites. (author)

Effects of boron addition on a-Si90Ge10:H films obtained by low frequency plasma enhanced chemical vapour deposition

International Nuclear Information System (INIS)

Perez, Arllene M; Renero, Francisco J; Zuniga, Carlos; Torres, Alfonso; Santiago, Cesar

2005-01-01

Optical, structural and electric properties of (a-(Si 90 Ge 10 ) 1-y B y :H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10 -3 to 10 1 Ω -1 cm -1 when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV

The Aggregation of Boron on the Tissues of Gold Fish (Carassius auratus Linnaeus, 1758

Directory of Open Access Journals (Sweden)

Tuncer Okan Genç

2015-03-01

Full Text Available In this study, it was aimed to determine the water-borne and food-borne boron accumulation in the liver and muscle tissues of Gold Fish (Carassius auratus Linnaeus, 1758. For each treatment, 12 individuals were. The water-borne boron treatments were applied as boron acid concentration of 1 mg/L, 10 mg/L and 20 mg/L in the aquarium water, while the food-borne boron treatments were prepared food contained the defined levels of boron (1 mg/kg, 5 mg/kg and 10 mg/kg as boric acid. The boron levels in the tissues were determined by an ICP-MS procedure. The maximum boron concentration was found in the 20mg/L water borne boron treatment in the liver tissue (1.78±0.02 mg/kg. In the water-borne boron treatments, the maximum Transfer Factor (TF was found in the 20mg/L boron concentration, and TF values were increased when the boron concentrations were decreasing. In the 1 mg/kg food-borne boron treatment, TF was found as 0, and increasing concentration of boron in the food caused an increase in TF reached about 0.06. This study suggested that the target organ for boron accumulation is the liver rather than the muscles and the accumulation of food-borne boron is lower when comparing water-borne boron.

LITHIUM-BERYLLIUM-BORON ISOTOPIC COMPOSITIONS IN METEORITIC HIBONITE: IMPLICATIONS FOR ORIGIN OF 10Be AND EARLY SOLAR SYSTEM IRRADIATION

International Nuclear Information System (INIS)

Liu, Ming-Chang; Nittler, Larry R.; Alexander, Conel M. O'D.; Lee, Typhoon

2010-01-01

NanoSIMS isotopic measurements of Li, Be, and B in individual hibonite grains extracted from the Murchison meteorite revealed that 10 B excesses correlate with the 9 Be/ 11 B ratios in 26 Al-free PLAty hibonite Crystals. From these data, an initial 10 Be/ 9 Be = (5.5 ± 1.6) x 10 -4 (2σ) and 10 B/ 11 B = 0.2508 ± 0.0015 can be inferred. On the other hand, chondritic boron isotopic compositions were found in 26 Al-bearing Spinel-HIBonite spherules, most likely due to contamination with normal boron. No 7 Li excesses due to 7 Be decay were observed. When combined with previously reported data, the new data yield the best defined 10 Be/ 9 Be = (5.3 ± 1.0) x 10 -4 (2σ) and 10 B/ 11 B = 0.2513 ± 0.0012 for PLACs. A comparison of this value and the best constrained 10 Be/ 9 Be = (8.8 ± 0.6) x 10 -4 in CV Ca-Al-rich inclusions supports a heterogeneous distribution of 10 Be and its protosolar irradiation origin. We consider two possible irradiation scenarios that could potentially lead to the observed Li-Be-B isotopic compositions in PLACs. Although in situ irradiation of solids with hibonite chemistry seems to provide the simplest explanation, more high quality data will be needed for quantitatively constraining the irradiation history.

Inverse-Frontal Chromatography studies on enrichment of Boron-10 using quaternery 4-vinylpyridine-divinylbenzene resin

International Nuclear Information System (INIS)

Bejawada, Venki; Mohapatra, C.; Rao, A.S.; Prasad, K.L.; Murthy, P.K.; Rao, A.K.; Singh, H.P.; Vithal, G.K.; Kumar, Sangita D.

2014-01-01

In order to enrich 10 B, band migration of boric acid-mannitol with hydrochloric acid solution was performed by inverse frontal chromatography on a porous, 25% crosslinked, 38% quaternized 4-vinylpyridine-divinylbenzene resin (py-resin). The work was initiated to replace the existing strong base anion exchange resin type-II (SBA-II) which is used in Boron Enrichment Plant (BEP) of heavy water plant Manuguru. Before its application in BEP, it is mandatory to evaluate py-resin for its performance. The studies showed that maximum of 40% 10 B enrichment observed after 13 m band movement and there was no further improvement, hence profile sampling carried out after 28 m. (author)

Irradiation Effects in Fortiweld Steel Containing Different Boron Isotopes

Energy Technology Data Exchange (ETDEWEB)

Grounes, M

1967-07-15

Tensile specimens and miniature impact specimens of the low alloyed pressure vessel steel Fortiweld have been irradiated at 265 deg C in R2 to two neutron doses, 6.5 x 10{sup 18} n/cm{sup 2} (> 1 MeV) and 4 x 10{sup 19} n/cm{sup 2} (thermal) and also 9.0 x 10{sup 18} n/cm{sup 2} (> 1 MeV) and 6 x 10{sup 19} n/cm{sup 2} (thermal). Material from three laboratory melts, in which the boron consisted of {sup 10}B, {sup 11}B and natural boron respectively, were investigated. The results both of tensile tests and impact tests with miniature impact specimens show that the {sup 10}B-alloyed material was changed more and the {sup 11}B-alloyed material was changed less than the material containing natural boron. At the higher neutron dose the increase in yield strength (0.2 % offset yield strength) was 11 kg/mm in the {sup 10}B containing material compared to 5 kg/mm in the {sup 11}B-containing material. The decrease in total elongation was 5 and 0 percentage units respectively. The transition temperature was increased 190 deg C at the higher neutron dose in the {sup 10}B-alloyed material, 40 deg C in the {sup 11}B-alloyed material and 80 deg C in the material containing natural boron.

Adsorption of boron from boron-containing wastewaters by ion exchange in a continuous reactor

International Nuclear Information System (INIS)

Yilmaz, A. Erdem; Boncukcuoglu, Recep; Yilmaz, M. Tolga; Kocakerim, M. Muhtar

2005-01-01

In this study, boron removal from boron-containing wastewaters prepared synthetically was investigated. The experiments in which Amberlite IRA 743, boron specific resin was used were carried out in a column reactor. The bed volume of resin, boron concentration, flow rate and temperature were selected as experimental parameters. The experimental results showed that percent of boron removal increased with increasing amount of resin and with decreasing boron concentration in the solution. Boron removal decreased with increasing of flow rate and the effect of temperature on the percent of total boron removal increased the boron removal rate. As a result, it was seen that about 99% of boron in the wastewater could be removed at optimum conditions

Potential of para-boronophenylalaninol as a boron carrier in boron neutron capture therapy, referring to that of its enantiomers

International Nuclear Information System (INIS)

Masunaga, S.; Sakurai, Y.; Ono, K.; Suziki, M.; Nagata, K.; Takagaki, M.; Nagasawa, H.

2003-01-01

We evaluated the potential of a newly developed 10 B-containing alpha-amino alcohol of para-boronophenylalanine- 10 B (BPA), para-boronophenylalaninol (BPAol), as a boron carrier in boron neutron capture therapy. C57BL mice bearing EL4 tumors and C3H/He mice bearing SCC VII tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously via implanted mini-osmotic pumps to label all proliferating (P) cells. After oral administration of L-BPA or D-BPA, or intraperitoneal injection of L-BPAol or D-BPAol, the tumors were irradiated with reactor thermal neutron beams. For the combination with mild temperature hyperthermia (MTH) and/or tirapazamine (TPZ), the tumors were heated at 40 degrees centigrade for 30 minutes right before neutron exposure, and/or TPZ was intraperitoneally injected 30 minutes before irradiation. The tumors were then excised, minced and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling ( = quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. Meanwhile, 6 hours after irradiation, tumor cell suspensions obtained in the same manner were used for determining the apoptosis frequency in Q cells. The apoptosis and MN frequency in total (P + Q) tumor cells were determined from the tumors that were not pretreated with BrdU. Without TPZ or MTH, L- and D-BPAol increased both frequencies markedly, especially for total cells. Although not significantly, L-BPA and D-BPAol increased both frequencies slightly more remarkably than D-BPA and L-BPAol, respectively. On combined treatment with both MTH and TPZ, the sensitivity difference between total and Q cells was markedly reduced. MTH increased the 10 B uptake of all 10 B-carriers into both tumor cells to some degree. Both L- and D-BPAol have potential as 10 B-carriers in neutron capture therapy, especially when combined with both MTH and TPZ

Internal stress control of boron thin film

Energy Technology Data Exchange (ETDEWEB)

Satomi, N.; Kitamura, M.; Sasaki, T.; Nishikawa, M. [Osaka Univ., Suita (Japan). Graduate Sch. of Eng.

1998-09-01

The occurrence of stress in thin films has led to serious stability problems in practical use. We have investigated the stress in the boron films to find the deposition condition of the boron films with less stress. It was found that the stress in the boron film varies sufficiently from compressive to tensile stress, that is from -1.0 to 1.4 GPa, depending on the evaporation conditions, such as deposition rate and the substrate temperature. Hydrogen ion bombardment resulted in the enhancement of the compressive stress, possibly due to ion peening effect, while under helium ion bombardment, stress relief was observed. The boron film with nearly zero stress was obtained by the evaporation at a deposition rate of 0.5 nm s{sup -1} and substrate temperature of 300 C. (orig.) 12 refs.

Internal stress control of boron thin film

International Nuclear Information System (INIS)

Satomi, N.; Kitamura, M.; Sasaki, T.; Nishikawa, M.

1998-01-01

The occurrence of stress in thin films has led to serious stability problems in practical use. We have investigated the stress in the boron films to find the deposition condition of the boron films with less stress. It was found that the stress in the boron film varies sufficiently from compressive to tensile stress, that is from -1.0 to 1.4 GPa, depending on the evaporation conditions, such as deposition rate and the substrate temperature. Hydrogen ion bombardment resulted in the enhancement of the compressive stress, possibly due to ion peening effect, while under helium ion bombardment, stress relief was observed. The boron film with nearly zero stress was obtained by the evaporation at a deposition rate of 0.5 nm s -1 and substrate temperature of 300 C. (orig.)

Spectrographic determination of traces of boron in steels

International Nuclear Information System (INIS)

Alduan, F.A.; Roca, M.

1976-01-01

A spectrographic method has been developed to determine quantitatively boron in steels in the 0.5 to 250 ppm concentration range. The samples are dissolved in acids and transformed into oxides, avoiding boron losses by the addition of mannitol. For the fluoride evolution of boron in the dc arc the following compounds have been considered: CuF 2 , LiF, NaF, and SrF 2 . CuF 2 , at a concentration of 10%, provides the highest line-to-background intensity ratio. An arc current of 5 amperes eliminates the interference from iron spectrum on the most sensitive boron line - B 2497.7 A. Variations in chromium and nickel contents have no effect on the analytical results. (author)

Design of thermal neutron beam based on an electron linear accelerator for BNCT.

Science.gov (United States)

Zolfaghari, Mona; Sedaghatizadeh, Mahmood

2016-12-01

An electron linear accelerator (Linac) can be used for boron neutron capture therapy (BNCT) by producing thermal neutron flux. In this study, we used a Varian 2300 C/D Linac and MCNPX.2.6.0 code to simulate an electron-photoneutron source for use in BNCT. In order to decelerate the produced fast neutrons from the photoneutron source, which optimize the thermal neutron flux, a beam-shaping assembly (BSA) was simulated. After simulations, a thermal neutron flux with sharp peak at the beam exit was obtained in the order of 3.09×10 8 n/cm 2 s and 6.19×10 8 n/cm 2 s for uranium and enriched uranium (10%) as electron-photoneutron sources respectively. Also, in-phantom dose analysis indicates that the simulated thermal neutron beam can be used for treatment of shallow skin melanoma in time of about 85.4 and 43.6min for uranium and enriched uranium (10%) respectively. Copyright © 2016. Published by Elsevier Ltd.

Evaluation of hypoxia-specific cytotoxic bioreductive agent-sodium borocaptate-10B conjugates as 10B-carriers in boron neutron capture therapy

International Nuclear Information System (INIS)

Masunaga, Shin-ichiro; Nagasawa, Hideko; Gotoh, Keiko

2006-01-01

The purpose of this study was to evaluate the usefulness of 5 new 10 B-compounds (TX-2091, TX-2095, TX-2097, TX-2100, and TX-2110) as 10 B-carriers in boron neutron capture therapy (BNCT). They were conjugates that had been synthesized from a hypoxia-specific cytotoxic bioreductive agent, quinoxaline oxide TX-402, and a clinically used 10 B-carrier, sodium borocaptate- 10 B (BSH). The 5 new compounds were hybrid compounds that have both a hypoxic cytotoxin unit and a thermal neutron-sensitizing unit, BSH. These new compounds and BSH were administered intraperitoneally to SCC VII tumor-bearing mice. Then, the 10 B concentrations in the tumors and normal tissues were measured by γ-ray spectrometry. Subsequently, SCC VII tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all proliferating (P) cells in the tumors, then treated with TX-2100, which was chosen based on the results of the above-mentioned biodistribution analyses, or BSH in the same manner as in the biodistribution studies. Right after irradiation, during which intratumor 10 B concentrations were kept at levels similar to each other, the tumors were excised, minced, and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling [=quiescent (Q) cells] was determined using immunofluorescence staining for BrdU. Meanwhile, the MN frequency in the total (P+Q) tumor cell population was determined from the tumors that were not pretreated with BrdU. Clonogenic cell survival was also determined in mice given no BrdU. 10 B biodistribution analyses in tumors, brain, skin, muscles, blood, and liver indicated that TX-2100 has the most favorable characteristics for concentrating a sufficient amount of 10 B in tumors and maintaining a high enough 10 B concentration during irradiation. In addition, TX-2100 had a significantly stronger radio-sensitizing effect with

Integral window/photon beam position monitor and beam flux detectors for x-ray beams

Science.gov (United States)

Shu, Deming; Kuzay, Tuncer M.

1995-01-01

A monitor/detector assembly in a synchrotron for either monitoring the position of a photon beam or detecting beam flux may additionally function as a vacuum barrier between the front end and downstream segment of the beamline in the synchrotron. A base flange of the monitor/detector assembly is formed of oxygen free copper with a central opening covered by a window foil that is fused thereon. The window foil is made of man-made materials, such as chemical vapor deposition diamond or cubic boron nitrate and in certain configurations includes a central opening through which the beams are transmitted. Sensors of low atomic number materials, such as aluminum or beryllium, are laid on the window foil. The configuration of the sensors on the window foil may be varied depending on the function to be performed. A contact plate of insulating material, such as aluminum oxide, is secured to the base flange and is thereby clamped against the sensor on the window foil. The sensor is coupled to external electronic signal processing devices via a gold or silver lead printed onto the contact plate and a copper post screw or alternatively via a copper screw and a copper spring that can be inserted through the contact plate and coupled to the sensors. In an alternate embodiment of the monitor/detector assembly, the sensors are sandwiched between the window foil of chemical vapor deposition diamond or cubic boron nitrate and a front foil made of similar material.

Oxytetracycline as a new analytical reagent for the spectrophotometric determination of boron

Energy Technology Data Exchange (ETDEWEB)

Narayana, G L

1984-05-01

Oxytetracycline hydrochloride, Terramycin, is introduced as a new reagent for the spectrophotometric determination of trace quantities of boron in concentrated sulphuric acid medium. The reagent has an absorption maximum at 430 nm, and that of the boron complex at 520 nm. The colored system conformed to Beer's law between 2 and 10 ..mu..g of boron at 520 nm. The molar absorptivity calculated on the basis of boron is 10,800 1 mol/sup -1/ cm/sup -1/. The composition of the complex has been shown to be 1:1 both by the slope ratio and molar ratio methods. 16 references.

Oxytetracycline as a new analytical reagent for the spectrophotometric determination of boron

International Nuclear Information System (INIS)

Narayana, G.L.

1984-01-01

Oxytetracycline hydrochloride, Terramycin, is introduced as a new reagent for the spectrophotometric determination of trace quantities of boron in concentrated sulphuric acid medium. The reagent has an absorption maximum at 430 nm, and that of the boron complex at 520 nm. The coloured system conformed to Beer's law between 2 and 10 μg of boron at 520 nm. The molar absorptivity calculated on the basis of boron is 10,800 1 mol -1 cm -1 . The composition of the complex has been shown to be 1:1 both by the slope ratio and molar ratio methods. (author)

Boron compounds in neutron capture therapy of tumors

International Nuclear Information System (INIS)

Strouf, O.; Gregor, V.

1986-01-01

In the selective incorporation of a sufficient amount of a compound containing boron isotope 10 B in the tumor tissue for neutron capture therapy, high efficiency is achieved in tumor destruction while sparing the surrounding tissues. In the treatment of brain tumors, 4-carboxy phenylboric acid and the disodium salt of mercaptoundecahydrododecaborate were successfully tested. The use of the compounds minimizes radiation damage to the blood stream of the brain. In case of melanomas the L-DOPA-borate complex, boronophenylalanine and chlorpromazine preparations containing 10 B are used. In the treatment of cancer of the reproductive organs, boron derivatives of estradiol and testosterone have been proven. The immunobiological procedure, i.e., the use of antibodies with bound boron compounds, is being intensively studied. (M.D.)

Design and construction of prompt-gamma spectroscopy facility applied to the boron determination; Diseno y construccion de una facilidad de espectrometria prompt-gamma aplicada a la determinacion de boro

Energy Technology Data Exchange (ETDEWEB)

Poblete, Victor; Henriquez, Carlos; Klein, Juan; Navarro, Gustavo [Comision Chilena de Energia Nuclear, Santiago (Chile). Centro de Estudios Nucleares La Reina, Comision Chis Nucleares La Reina, Comision Chi Reina

1997-12-31

A prompt-gamma spectroscopy facility was developed using the south tangential neutron beam of the RECH-1 research reactor for boron determination. The implementation of a thermal neutron beam was performed considering different aspects such as biological protection of working area and the beam collimation for a Ge detector, design and sample holder selection, standards and sample preparation. One ppm of Boron in different samples with counting-rate of 20 minutes and a good accuracy were determined. (author). 5 refs.

Real-time boronization in PBX-M using erosion of solid boronized targets

International Nuclear Information System (INIS)

Kugel, H.W.; Timberlake, J.; Bell, R.; LeBlanc, B.; Okabayashi, M.; Paul, S.; Tighe, W.; Hirooka, Y.

1994-11-01

Thirty one real-time boronizations were applied to PBX-M using the plasma erosion of solid target probes. More than 17 g of boron were deposited in PBX-M using this technique. The probes were positioned at the edge plasma to optimize vaporization and minimize spallation. Auger depth profile analysis of poloidal and toroidal deposition sample coupon arrays indicate that boron was transported by the plasma around the torus and deep into the divertors. During discharges with continuous real-time boronization, low-Z and high-Z impurities decreased rapidly as plasma surfaces were covered during the first 20-30 discharges. After boronization, a short-term improvement in plasma conditions persisted prior to significant boron erosion from plasma surfaces, and a longer term, but less significant improvement persisted as boron farther from the edge continued gettering. Real-time solid target boronization has been found to be very effective for accelerating conditioning to new regimes and maintaining high performance plasma conditions

Effects of boron addition on a-Si(90)Ge(10):H films obtained by low frequency plasma enhanced chemical vapour deposition.

Science.gov (United States)

Pérez, Arllene M; Renero, Francisco J; Zúñiga, Carlos; Torres, Alfonso; Santiago, César

2005-06-29

Optical, structural and electric properties of (a-(Si(90)Ge(10))(1-y)B(y):H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10(-3) to 10(1) Ω(-1) cm(-1) when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV.

Combustion Performance of a Staged Hybrid Rocket with Boron addition

Science.gov (United States)

Lee, D.; Lee, C.

2018-04-01

In this paper, the effect of boron on overall system specific impulse was investigated. Additionally, a series of combustion tests was carried out to analyze and evaluate the effect of boron addition on O/F variation and radial temperature profiles. To maintain the hybrid rocket engine advantages, upper limit of boron contents in solid fuel was set to be 10 wt%. The results also suggested that, when adding boron to solid fuel, it helped to provide more uniform radial temperature distribution and also to increase specific impulse by 3.2%.

Ceramic silicon-boron-carbon fibers from organic silicon-boron-polymers

Science.gov (United States)

Riccitiello, Salvatore R. (Inventor); Hsu, Ming-Ta S. (Inventor); Chen, Timothy S. (Inventor)

1993-01-01

Novel high strength ceramic fibers derived from boron, silicon, and carbon organic precursor polymers are discussed. The ceramic fibers are thermally stable up to and beyond 1200 C in air. The method of preparation of the boron-silicon-carbon fibers from a low oxygen content organosilicon boron precursor polymer of the general formula Si(R2)BR(sup 1) includes melt-spinning, crosslinking, and pyrolysis. Specifically, the crosslinked (or cured) precursor organic polymer fibers do not melt or deform during pyrolysis to form the silicon-boron-carbon ceramic fiber. These novel silicon-boron-carbon ceramic fibers are useful in high temperature applications because they retain tensile and other properties up to 1200 C, from 1200 to 1300 C, and in some cases higher than 1300 C.

Sodium borocaptate (BSH) for Boron Neutron Capture Therapy (BNCT) in the hamster cheek pouch oral cancer model: boron biodistribution at 9 post administration time-points

International Nuclear Information System (INIS)

Garabalino, M.A.; Heber, E.M.; Monti, Hughes A.; Molinari, A.J.; Pozzi, E.C.C.; Trivillin, V.A.; Schwint, Amanda E.

2011-01-01

The therapeutic success of Boron Neutron Capture Therapy (BNCT) depends centrally on boron concentration in tumor and healthy tissue. We previously demonstrated the therapeutic efficacy of boronophenylalanine (BPA) and sodium decahydrodecaborate (GB-10) as boron carriers for BNCT in the hamster cheek pouch oral cancer model. Given the clinical relevance of sodium mercaptoundecahydro-closo-dodecaborate (BSH) as a boron carrier, the aim of the present study was to expand the ongoing BSH biodistribution studies in the hamster cheek pouch oral cancer model. In particular, we studied 3 additional post-administration time-points and increased the sample size corresponding to the time-points evaluated previously, to select more accurately the post-administration time at which neutron irradiation would potentially confer the greatest therapeutic advantage. BSH was dissolved in saline solution in anaerobic conditions to avoid the formation of the dimer BSSB and its oxides which are toxic. The solution was injected intravenously at a dose of 50 mg 10 B/kg (88 mg BSH / kg). Different groups of animals were killed humanely at 7, 8, and 10 h after administration of BSH. The sample size corresponding to the time-points 3, 4, 6, 9 and 12 h was increased. Samples of blood, tumor, precancerous tissue, normal pouch tissue, cheek mucosa, parotid gland, palate, skin, tongue, spinal cord marrow, brain, liver, kidney, spleen and lung were processed for boron measurement by Optic Emission Spectroscopy (ICP-OES). Boron concentration in tumor peaked to 24-34 ppm, 3-10 h post-administration of BSH, with a spread in values that resembled that previously reported in other experimental models and human subjects. The boron concentration ratios tumor/normal pouch tissue and tumor/blood ranged from 1.3 to 1.8. No selective tumor uptake was observed at any of the time points evaluated. The times post-administration of BSH that would be therapeutically most useful would be 5, 7 and 9 h. The

A study on the behavior of boron in iron-base alloys by neutron induced autoradiography

Energy Technology Data Exchange (ETDEWEB)

Jang, Jin Sung; Rhee, Chang Kyu; Cho, Hae Dong; Han, Chang Hee; Lee, Chang Hee; Jung, Jung Hwan; Kim, Yi Kyung; Lee, Yong Bok

2001-02-01

Boron is widely utilized in steel or alloy making to improve certain properties. However, due to its lightness boron is difficult to detect or characterize its behavior even through TEM/EDS or EELS techniques. Although many companies recognize the beneficial effects of boron, the role or mechanism of the boron is not yet clearly understood. Therefore it is required to develop the autoradiography technique to elucidate the boron behavior in alloys. As the only institute operating research reactor in the country, it would be the responsibility of the institute to develop the technique and provide it to the industries. Quantitative analyses of boron in type 316 L stainless steel by neutron induced autoradiography was attempted in this study. Nine experimental reference alloys with different amount of boron were prepared and reliable chemical composition data were obtained. Autoradiographs of reference materials with three different neutron fluences ( 1.9 10{sup 13}, 1.9 10{sup 14} and 1.9 10{sup 15}/cm{sup 2} ) were obtained and a trial calibration curve of boron content vs. track density was acquired.

BC-454 boron-loaded plastic scintillator

International Nuclear Information System (INIS)

Bellian, J.G.

1984-01-01

Prototype samples of plastic scintillators containing up to 10% by weight of natural boron have been produced. The maximum size scintillators made to date are 28 mm dia. x 100 mm long. Rods containing up to 2% boron are now made routinely and work is progressing on higher concentrations. The plastics are clear and emit the same blue fluorescence as other common plastic scintillators. It is expected that rods up to 3'' dia. containing 5% boron will be produced during the next few months. BC-454 is particularly useful in neutron research, materials studies, some types of neutron dosimetry, and monitoring of medium to high energy neutrons in the presence of other types radiation. It combines attractive features that enhance its usefulness to the physics community

Monte Carlo simulation of boron-ion implantation into single-crystal silicon

International Nuclear Information System (INIS)

Klein, K.M.

1991-01-01

A physically based Monte Carlo boron implantation model developed comprehends previously neglected but important implant parameters such as native oxide layers, wafer temperature, beam divergence, tilt angle, rotation (twist) angle, and dose, in addition to energy. This model uses as its foundation the MARLOWE Monte Carlo simulation code developed at Oak Ridge National Laboratory for the analysis of radiation effects in materials. This code was carefully adapted for the simulation of ion implantation, and a number of significant improvements have been made, including the addition of atomic pair specific interatomic potentials, the implementation of a newly developed local electron concentration dependent electronic stopping model, and the implementation of a newly developed cumulative damage model. This improved version of the code, known as UT-MARLOWE, allows boron implantation profiles to be accurately predicted as a function of energy, tilt angle, rotation angle, and dose. This code has also been used in the development and implementation of an accurate and efficient two-dimensional boron implantation model

Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols

International Nuclear Information System (INIS)

Bortolussi, Silva; Ciani, Laura; Postuma, Ian; Protti, Nicoletta; Luca Reversi,; Bruschi, Piero; Ferrari, Cinzia; Cansolino, Laura; Panza, Luigi; Ristori, Sandra; Altieri, Saverio

2014-01-01

The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recently set-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. This technique was calibrated and the obtained results were cross checked with those of α spectrometry, in order to validate them. The comparisons were performed using tissues taken form animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations. - Highlights: • A method for 10B measurements in samples based on neutron autoradiography was developed. • The results were compared with those of alpha spectrometry applied on tissue and cell samples. • Boronated liposomes were developed and administered to osteosarcoma cell cultures. • Neutron autoradiography was employed to measure boron concentration due to liposomes. • Liposomes were proved to be more effective in concentrating boron in cells than BPA

Study of shallow junction formation by boron-containing cluster ion implantation of silicon and two-stage annealing

Science.gov (United States)

Lu, Xin-Ming

Shallow junction formation made by low energy ion implantation and rapid thermal annealing is facing a major challenge for ULSI (ultra large scale integration) as the line width decreases down to the sub micrometer region. The issues include low beam current, the channeling effect in low energy ion implantation and TED (transient enhanced diffusion) during annealing after ion implantation. In this work, boron containing small cluster ions, such as GeB, SiB and SiB2, was generated by using the SNICS (source of negative ion by cesium sputtering) ion source to implant into Si substrates to form shallow junctions. The use of boron containing cluster ions effectively reduces the boron energy while keeping the energy of the cluster ion beam at a high level. At the same time, it reduces the channeling effect due to amorphization by co-implanted heavy atoms like Ge and Si. Cluster ions have been used to produce 0.65--2keV boron for low energy ion implantation. Two stage annealing, which is a combination of low temperature (550°C) preannealing and high temperature annealing (1000°C), was carried out to anneal the Si sample implanted by GeB, SiBn clusters. The key concept of two-step annealing, that is, the separation of crystal regrowth, point defects removal with dopant activation from dopant diffusion, is discussed in detail. The advantages of the two stage annealing include better lattice structure, better dopant activation and retarded boron diffusion. The junction depth of the two stage annealed GeB sample was only half that of the one-step annealed sample, indicating that TED was suppressed by two stage annealing. Junction depths as small as 30 nm have been achieved by two stage annealing of sample implanted with 5 x 10-4/cm2 of 5 keV GeB at 1000°C for 1 second. The samples were evaluated by SIMS (secondary ion mass spectrometry) profiling, TEM (transmission electron microscopy) and RBS (Rutherford Backscattering Spectrometry)/channeling. Cluster ion implantation

Low energy implantation of boron with decaborane ions

Science.gov (United States)

Albano, Maria Angela

The goal of this dissertation was to determine the feasibility of a novel approach to forming ultra shallow p-type junctions (tens of nm) needed for future generations of Si MOS devices. In the new approach, B dopant atoms are implanted by cluster ions obtained by ionization of decaborane (B 10H14) vapor. An experimental ion implanter with an electron impact ion source and magnetic mass separation was built at the Ion Beam and Thin Film Research Laboratory at NJIT. Beams of B10Hx+ ions with currents of a few microamperes and energies of 1 to 12 keV were obtained and used for implantation experiments. Profiles of B and H atoms implanted in Si were measured by Secondary Ion Mass Spectroscopy (SIMS) before and after rapid thermal annealing (RTA). From the profiles, the junction depth of 57 nm (at 1018 cm-3 B concentration) was obtained with 12 keV decaborane ions followed by RTA. The dose of B atoms that can be implanted at low energy into Si is limited by sputtering as the ion beam sputters both the matrix and the implanted atoms. As the number of sputtered B atoms increases with the implanted dose and approaches the number of the implanted atoms, equilibrium of B in Si is established. This effect was investigated by comparison of the B dose calculated from the ion beam integration with B content in the sample measured by Nuclear Reaction Analysis (NRA). Maximum (equilibrium) doses of 1.35 x 1016 B cm -2 and 2.67 x 1016 B cm-2 were obtained at the beam energies of 5 and 12 keV, respectively. The problem of forming shallow p-type junctions in Si is related not only to implantation depth, but also to transient enhanced diffusion (TED). TED in Si implanted with B10Hx+ was measured on boron doping superlattice (B-DSL) marker layers. It was found that TED, following decaborane implantation, is the same as with monomer B+ ion implantation of equivalent energy and that it decreases with the decreasing ion energy. (Abstract shortened by UMI.)

Boron neutron capture therapy in cancer: past, present and future

Energy Technology Data Exchange (ETDEWEB)

Pisarev, Mario A.; Dagrosa, Maria Alejandra; Juvenal, Guilermo J. [National Atomic Energy Commission, Buenos Aires (Argentina). Div. of Nuclear Biochemistry; University of Buenos Aires (Argentina). School of Medicine. Dept. of Human Biochemistry

2007-07-15

Undifferentiated thyroid cancer (UTC) is a very aggressive tumor with no effective treatment, since it lacks iodine uptake and does not respond to radio or chemotherapy. The prognosis of these patients is bad, due to the rapid growth of the tumor and the early development of metastasis. Boron neutron capture therapy (BNCT) is based on the selective uptake of certain boron non-radioactive compounds by a tumor, and the subsequent irradiation of the area with an appropriate neutron beam. {sup 10}B is then activated to {sup 11}B, which will immediately decay releasing alpha particles and {sup 7}Li, of high linear energy transfer (LET) and limited reach. Clinical trials are being performed in patients with glioblastoma multiform and melanoma. We have explored its possible application to UTC. Our results demonstrated that a cell line of human UTC has a selective uptake of borophenylalanine (BPA) both in vitro and after transplantation to nude mice. Treatment of mice by BNCT led to a complete control of growth and cure of 100% of the animals. Moreover dogs with spontaneous UTC also have a selective uptake of BPA. At the present we are studying the biodistribution of BPA in patients with UTC before its application in humans. (author)

Flux distribution in phantom for biomedical use of beam-type thermal neutrons

International Nuclear Information System (INIS)

Aoki, Kazuhiko; Kobayashi, Tooru; Kanda, Keiji; Kimura, Itsuro

1985-01-01

For boron neutron capture therapy, the thermal neutron beam is worth using as therapeutic neutron irradiation without useless and unfavorable exposure of normal tissues around tumor and for microanalysis system to measure ppm-order 10 B concentrations in tissue and to search for the location of the metastasis of tumor. In the present study, the thermal neutron flux distribution in a phantom, when beam-type thermal neutrons were incident on it, was measured at the KUR Neutron Guide Tube. The measurements were carried out by two different methods using indium foil. The one is an ordinary foil activation technique by using the 115 In(n, γ) 116m 1 In reactions, while the other is to detect γ-rays from the 115 In(n, γ) 116m 2 In reactions during neutron irradiations with a handy-type Ge detector. The calculations with DOT 3.5 were performed to examine thermal neutron flux in the phantom for various beam size and phantom size. The experimental and calculated results are in good agreement and it is shown that the second type measurement has a potential for practical application as a new monitoring system of the thermal neutron flux in a living body for boron neutron capture therapy. (author)

Aspects of the chemistry of boron

International Nuclear Information System (INIS)

Moellinger, H.

1976-01-01

Crystal phases of elementary boron are reviewed as well as boron-sulphur, boron-selenum, boron-tellurium, and boron-nitrogen compounds, carboranes, and boron-carbohydrate complexes. A boron cadastre of rivers and lakes serves to illustrate the role of boron in environmental protection. Technically relevant boron compounds and their uses are mentioned. (orig.) 891 HK/orig. 892 MB [de

Coupling of dextrans conjugated with boron to γ globulin: a model for NCT

International Nuclear Information System (INIS)

Elmore, J.J. Jr.; Borg, D.C.; Micca, P.; Gabel, D.

1982-01-01

To achieve the selective localization of boron in or on cancer cells or other target cells, the authors have elected to use water-soluble dextrans as intermediate carriers. This permits each MCA molecule to target many atoms of boron-10 to the specified antigenic receptors while only 5 to 10 of the amino acid residues of the protein are conjugated by dextrans carrying boron-10. As a result, there should be little of the loss of receptor specificity or affinity

Application of the boron neutron capture therapy to undifferentiated thyroid cancer using two boron compounds (BPA and BOPP)

International Nuclear Information System (INIS)

Viaggi, Mabel; Dagrosa, Maria A.; Juvenal, Guillermo J.; Pisarev, Mario A.; Longhino, Juan M.; Blaumann, Hernan R.; Calzetta Larrieu, Osvaldo A.; Kahl, Stephen B.

2004-01-01

We have shown the selective uptake of boronophenylalanine (BPA) by undifferentiated thyroid cancer (UTC) human cell line ARO, both in vitro and in vivo. Moreover, a 50% histologic cure of mice bearing the tumor was observed when the complete boron neutron capture therapy was applied. More recently we have analyzed the biodistribution of BOPP (tetrakis-carborane carboxylate ester of 2,4-bis-(ba-dihydroxyethyl)-deutero-porphyrin IX) and showed that when BOPP was injected 5 days before BPA, and the animals were sacrificed 60 min after the ip injection of BPA, a significant increase in boron uptake by the tumor was found (38-45ppm with both compounds Vs. 20 ppm with BPA alone). Five days post the ip BOPP injection and 1 hr after BPA, the ratios were: tumor/blood 3,75; tumor /distal skin 2. Other important ratios were tumor/thyroid 6,65 and tumor/lung 3,8. The present studies were performed in mice transplanted with ARO cells and injected with BOPP and BPA. Only in mice treated with the neutron beam and injected with the boronated compounds we observed a 100% control of tumor growth. Two groups of mice received different total absorbed doses: 3.00 and 6.01 Gy, but no further improvement in the outcome was found compared to the previous results using BPA alone (4.3 Gy). (author)

Boron determination in tourmaline by neutron induced radiography

Energy Technology Data Exchange (ETDEWEB)

Qureshi, A.A. E-mail: aaqureshi@pinstech.org.pk; Akram, M.; Ayub Khan, M.; Khattak, N.U.; Qureshi, I.E.; Khan, H.A

2001-06-01

The technique of neutron induced radiography has been applied to determine the boron concentration and its spatial distribution in mineral tourmaline collected from Swat Tourmaline Granite, Northern Pakistan. The technique involves the simultaneous irradiation of sample and a standard fixed on a track detector with thermal neutrons and the counting of alpha and {sup 7}Li tracks produced in the detector from the nuclear reaction {sup 10}B(n,{alpha}){sup 7}Li. Boron concentration is determined by comparing the {sup 7}Li and alpha particle tracks density with that of a standard of known boron concentration. Boron concentration in tourmaline has been found to be (3.40{+-}0.01)% in this study which is on the upper side within the normal range (2.5-3.8)% reported in the world. The presence of somewhat higher concentration of boron in tourmaline indicates that the Swat Tourmaline Granite was generated as a late stage hydrothermal activity during the Himalayan Orogeny.

Implementation and performance of beam smoothing on 10 beams of the Nova Laser

International Nuclear Information System (INIS)

Pennington, D.M.

1997-01-01

Recent simulations and experiments on Nova indicate that some level of smoothing may be required to suppress filamentation in plasmas on the National Ignition Facility (NIF), resulting in the addition of 1-D smoothing capability to the current baseline design. Control of stimulated Brillouin scattering (SBS) and filamentation is considered essential to the success of laser fusion because they affect the amount and location of laser energy delivered to the x-ray conversion region (hohlraum wall) for indirect drive and to the absorptive region for direct drive, Smoothing by spectral dispersion (SSD)[1], reduces these instabilities by reducing nonuniformities in the focal irradiance when averaged over a finite time interval. We have installed SSD on Nova to produce beam smoothing on all 10 beam lines. A single dispersion grating is located in a position common to all 10 beam lines early in the preamplifier chain. This location limits the 1 ω bandwidth to 2.2 (angstrom) with sufficient dispersion to displace the speckle field of each frequency component at the target plane by one half speckle diameter. Several beam lines were modified to allow orientation of the dispersion on each arm relative to the hohlraum wall. After conversion to the third harmonic the beam passes through a kinoform phase plate (KPP) designed to produce an elliptical spot at best focus. The KPPs produce a focal spot having an elliptical flat-top envelope with a superimposed speckle pattern. Over 93% of the energy is contained in the central 400 km. Calculations indicate a 16% rms. intensity variance will be reached after 330 ps for a single beam

Boron Neutron Capture Therapy activity of diffused tumors at TRIGA Mark II in Pavia

Energy Technology Data Exchange (ETDEWEB)

Bortolussi, S.; Stella, S.; De Bari, A.; Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy)]|[National Institute of Nuclear Physics (INFN), Pavia (Italy); Bruschi, P.; Bakeine, J.G. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Clerici, A.; Ferrari, C.; Zonta, C.; Zonta, A. [Department of Surgery, University of Pavia, Pavia (Italy); Nano, R. [Department of Animal Biology, University of Pavia, Pavia (Italy)

2008-10-29

The Boron neutron Capture Therapy research in Pavia has a long tradition: it begun more than 20 years ago at the TRIGA Mark II reactor of the University. A technique for the treatment of the hepatic metastases was developed, consisting in explanting the liver treated with {sup 10}B, irradiating it in the thermal column of the reactor, and re-implanting the organ in the patient. In the last years, the possibility of applying BNCT to the lung tumours using epithermal collimated neutron beams and without explanting the organ, is being explored. The principal obtained results of the BNCT research will be presented, with particular emphasis on the following aspects: a) the project of a new thermal column configuration to make the thermal neutron flux more uniform inside the explanted liver, b) the Monte Carlo study by means of the MCNP code of the thermal neutron flux distribution inside a patient's thorax irradiated with epithermal neutrons, and c) the measurement of the boron concentration in tissues by (n,{alpha}) spectroscopy and neutron autoradiography. (authors)

Boron Neutron Capture Therapy activity of diffused tumors at TRIGA Mark II in Pavia

International Nuclear Information System (INIS)

Bortolussi, S.; Stella, S.; De Bari, A.; Altieri, S.; Bruschi, P.; Bakeine, J.G.; Clerici, A.; Ferrari, C.; Zonta, C.; Zonta, A.; Nano, R.

2008-01-01

The Boron neutron Capture Therapy research in Pavia has a long tradition: it begun more than 20 years ago at the TRIGA Mark II reactor of the University. A technique for the treatment of the hepatic metastases was developed, consisting in explanting the liver treated with 10 B, irradiating it in the thermal column of the reactor, and re-implanting the organ in the patient. In the last years, the possibility of applying BNCT to the lung tumours using epithermal collimated neutron beams and without explanting the organ, is being explored. The principal obtained results of the BNCT research will be presented, with particular emphasis on the following aspects: a) the project of a new thermal column configuration to make the thermal neutron flux more uniform inside the explanted liver, b) the Monte Carlo study by means of the MCNP code of the thermal neutron flux distribution inside a patient's thorax irradiated with epithermal neutrons, and c) the measurement of the boron concentration in tissues by (n,α) spectroscopy and neutron autoradiography. (authors)

Analysis and separation of boron isotopes; Analyse et separation des isotopes du bore

Energy Technology Data Exchange (ETDEWEB)

Perie, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-11-01

The nuclear applications of boron-10 justify the study of a method of measurement of its isotopic abundance as well as of very small traces of boron in different materials. A systematic study of thermionic emission of BO{sub 2}Na{sub 2}{sup +} has been carried out. In the presence of a slight excess of alkalis, the thermionic emission is considerably reduced. On the other hand, the addition of a mixture of sodium hydroxide-glycerol (or mannitol) to borax permits to obtain an intense and stable beam. These results have permitted to establish an operative method for the analysis of traces of boron by isotopic dilution. In other respects, the needs of boron-10 in nuclear industry Justify the study of procedures of separation of isotopes of boron. A considerable isotopic effect has been exhibited in the chemical exchange reaction between methyl borate and borate salt in solution. In the case of exchange between methyl borate and sodium borate, the elementary separation factor {alpha} is: {alpha}=(({sup 11}B/{sup 10}B)vap.)/(({sup 11}B/{sup 10}B)liq.)=1.03{sub 3}. The high value of this elementary effect has been multiplied in a distillation column in which the problem of regeneration of the reactive has been resolved. An alternative procedure replacing the alkali borate by a borate of volatile base, for example diethylamine, has also been studied ({alpha}=1,02{sub 5} in medium hydro-methanolic with 2,2 per cent water). (author) [French] Les applications nucleaires du bore 10 justifient l'etude d'une methode de mesure de son abondance isotopique dans divers materiaux ainsi que le dosage de tres faibles traces de bore. Une etude systematique de l'emission thermoionique de BO{sub 2} Na{sub 2}{sup +} a ete effectuee. En presence d'un leger exces d'alcalins, l'emission thermoionique est considerablement reduite. Par contre l'addition au borax d'un melange soude-glycerol (ou mannitol) permet d'obtenir un faisceau stable et intense. Ces resultats ont permis d'etablir un mode

Design of neutron beams at the Argonne Continuous Wave Linac (ACWL) for boron neutron capture therapy and neutron radiography

International Nuclear Information System (INIS)

Zhou, X.L.; McMichael, G.E.

1994-01-01

Neutron beams are designed for capture therapy based on p-Li and p-Sc reactions using the Argonne Continuous Wave Linac (ACWL). The p-Li beam will provide a 2.5 x 10 9 n/cm 2 s epithermal flux with 7 x 10 5 γ/cm 2 s contamination. On a human brain phantom, this beam allows an advantage depth (AD) of 10 cm, an advantage depth dose rate (ADDR) of 78 cGy/min and an advantage ratio (AR) of 3.2. The p-Sc beam offers 5.9 x 10 7 n/cm 2 s and a dose performance of AD = 8 cm and AR = 3.5, suggesting the potential of near-threshold (p,n) reactions such as the p-Li reaction at E p = 1.92 MeV. A thermal radiography beam could also be obtained from ACWL

Spectrophotometric determination of boron by solvent extraction with hydrobenzoin and crystal violet

International Nuclear Information System (INIS)

Sato, Shigeya; Uchikawa, Sumio

1982-01-01

A highly sensitive and simple method for the spectrophotometric determination of boron was developed. Boron was found to react with hydrobenzoin in weak alkaline medium to form a complex anion extractable into benzene with crystal violet, and the measurement of the absorbance of crystal violet in the extract at 600 nm enabled the determination of boron indirectly. The recommended procedure is as follows: Take an aliquot of the boron solution (2.0 x 10 - 4 mol l - 1 ) into a 10-ml test tube. Add 1 ml of carbonate buffer solution (pH 9.4) and 0.25 ml of crystal violet solution (1.0 x 10 - 2 mol l - 1 ), and dilute the mixed solution to 4 ml with deionized water. Shake the solution with 4 ml of benzene solution containing hydrobenzoin (2.0 x 10 - 2 mol l - 1 ) for 2 min. Measure the absorbance of the organic phase at 600 nm using a 10-mm glass cell against benzene. The calibration curve obeyed Beer's law on the concentration range from 2.5 x 10 - 6 mol l - 1 to 2.5 x 10 - 5 mol l - 1 of boron, and the apparent molar absorptivity was 3.0 x 10 4 l mol - 1 cm - 1 at 20 0 C. It was found that many kinds of co-existing ions interfered with the determination. However, this method was applicable to the determination of boron in sea water when chloride ion and cations such as Ca(II) and Mg(II) were previously eliminated by treating the sample solution with Ag 2 O and cation exchanger resin. The proposed method is a very simple and rapid one, because this method does not require apparatus other than common laboratories and the evaporation to dryness of sample or removal of the excess of reagent. (author)

Electronic structures and three-dimensional effects of boron-doped carbon nanotubes

International Nuclear Information System (INIS)

Koretsune, Takashi; Saito, Susumu

2008-01-01

We study boron-doped carbon nanotubes by first-principles methods based on the density functional theory. To discuss the possibility of superconductivity, we calculate the electronic band structure and the density of states (DOS) of boron-doped (10,0) nanotubes by changing the boron density. It is found that the Fermi level density of states D(ε F ) increases upon lowering the boron density. This can be understood in terms of the rigid band picture where the one-dimensional van Hove singularity lies at the edge of the valence band in the DOS of the pristine nanotube. The effect of three-dimensionality is also considered by performing the calculations for bundled (10,0) nanotubes and boron-doped double-walled carbon nanotubes (10,0)/(19,0). From the calculation of the bundled nanotubes, it is found that interwall dispersion is sufficiently large to broaden the peaks of the van Hove singularity in the DOS. Thus, to achieve the high D(ε F ) using the bundle of nanotubes with single chirality, we should take into account the distance from each nanotube. In the case of double-walled carbon nanotubes, we find that the holes introduced to the inner tube by boron doping spread also on the outer tube, while the band structure of each tube remains almost unchanged.

Comparison of boron and neon damage effects in boron ion-implanted resistors

International Nuclear Information System (INIS)

MacIver, B.A.

1975-01-01

Boron and neon damage implants were used in fabricating integrated-circuit resistors in silicon. Resistor properties were studied as functions of damaging ion species and dose. Sheet resistances in the 10 000 Ω/square range were obtained with low temperature and voltage sensitivities and d.c. isolation. (author)

The ternary system nickel-boron-silicon

International Nuclear Information System (INIS)

Lugscheider, E.; Reimann, H.; Knotek, O.

1975-01-01

The ternary system Nickel-Boron-Silicon was established at 850 0 C by means of X-ray diffraction, metallographic and micro-hardness examinations. The well known binary nickel borides and silicides resp. were confirmed. In the boron-silicon system two binary phases, SiBsub(4-x) with x approximately 0.7 and SiB 6 were found the latter in equilibrium with the β-rhombohedral boron. Confirming the two ternary silicon borides a greater homogeneity range was found for Ni 6 Si 2 B, the phase Nisub(4,6)Si 2 B published by Uraz and Rundqvist can better be described by the formula Nisub(4.29)Si 2 Bsub(1.43). In relation to further investigations we measured melting temperatures in ternary Ni-10 B-Si alloys by differential thermoanalysis. (author)

The determination of boron and carbon in reactor grade boron carbide

International Nuclear Information System (INIS)

Crossley, D.; Wood, A.J.; McInnes, C.A.J.; Jones, I.G.

1978-09-01

The sealed tube method of dissolution at high temperature and pressure has been successfully applied in the analysis of reactor grade boron carbide for the determination of boron. A 50 mg sample of boron carbide is completely dissolved by heating with concentrated nitric acid in a sealed tube at 300 0 C. The boron content of the resultant sample solution is determined by the mannitol potentiometric titration method. The precision of the method for the determination of 2.5 mg of boron using the Harwell automatic potentiometric titrator is 0.2% (coefficient of variation). The carbon content of a boron carbide sample is determined by combustion of the sample at 1050 0 C in a stream of oxygen using vanadium pentoxide to ensure the complete oxidation of the sample. The carbon dioxide produced from the sample is measured manometrically and the precision of the method for the determination of 4 mg of carbon is 0.4% (coefficient of variation). (author)

Boron uptake measurements in metastatic tumours in rat lung

International Nuclear Information System (INIS)

Bortolussi, S.; Altieri, S.; Bruschi, P.

2006-01-01

Lung carcinoma is the leading cause of cancer mortality worldwide; despite the introduction over the last few years of new therapeutic agents, very little progress has been made in terms of survival, and the overall prognosis for these patients remains poor. For these reasons any efforts to find and validate new effective therapeutic procedures for lung cancer are very timely and essential. To study the possibility to apply BNCT in the cure of diffuse pulmonary tumours, we created a BNCT Lung Project in Pavia, supported by Ministry of Education, University and Research (MIUR), in which Physicists, Medical Doctors and Biologists are involved. The first steps were; 1. development of an animal model for Boron uptake measurements in healthy and tumour lung tissues; 2. evaluation of the possibility to treat patients with epithermal neutron beams (See S. Altieri et al., this Conference); 3. in-vitro study of BNCT efficacy (see A. Zonta et al.). Spatial Boron distribution by neutron radiography in lung metastases from Colon Adenocarcinoma is reported; furthermore we present preliminary results of Boron concentration measures in rat lung tissues. The measures were performed using alpha spectrometry in thin tissue samples. (author)

Grain refinement of cast titanium alloys via trace boron addition

International Nuclear Information System (INIS)

Tamirisakandala, S.; Bhat, R.B.; Tiley, J.S.; Miracle, D.B.

2005-01-01

The grain size of as-cast Ti-6Al-4V is reduced by about an order of magnitude from 1700 to 200 μm with an addition of 0.1 wt.% boron. A much weaker dependence of reduction in grain size is obtained for boron additions from >0.1% to 1.0%. Similar trends were observed in boron-modified as-cast Ti-6Al-2Sn-4Zr-2Mo-0.1Si

Neutron Damage in Steels Containing Small Amounts of Boron

Energy Technology Data Exchange (ETDEWEB)

Myers, H P

1961-05-15

Certain low alloy steels contain small amounts (0.003 to 0.007 w/o) of boron which element contributes to the development of the air hardening properties of these steels. Such steels appear attractive for reactor pressure vessel construction but the question arises whether they will, due to the (n,{alpha}) reaction in boron, be more susceptible to neutron radiation damage than other steels which do not contain boron. We have attempted to estimate the importance of damage arising through boron fission relative to that caused by fast neutrons by assuming that the two sources of damage will be proportional to the numbers of displaced atoms produced in the two processes when no annealing or re combination of defects occurs. Within the approximations used we conclude that in a neutron spectrum which may be represented by an equivalent thermal flux {phi}{sub t} and an equivalent fast flux at 1 MeV of {phi}{sub f}, then D, the ratio of damage to boron fission to that caused by fast neutrons, is D = 4.5 x 10{sup -2} {phi}{sub t}/{phi}{sub f} (for 0. 003 w/o B). For the conditions at the inside of the reactor tank to R3 this would imply D = 1.2 x 10{sup -2} , i.e. if the R3 tank were built with a steel containing 0.003 w/o B then damage due to boron fission would be only {approx} 1 % of that caused by fast neutrons. Further problems with such steels as here discussed are the probability of embrittlement due to the introduction of boron fission fragments lithium and helium and the possibility of a radiation enhanced diffusion of boron which might lead to accentuated slow strain rate embrittlement. We argue that none of these problems should arise. It is concluded that a constructional steel containing 0.003 to 0.007 w/o B should not on this account be more susceptible to radiation damage than other non boron containing steels.

Accelerator conceptual design and needs of nuclear data for boron neutron capture therapy

International Nuclear Information System (INIS)

Sasaki, Makoto; Yamanaka, Toshiyuki; Yokobori, Hitoshi

1999-01-01

An optimization study has been made on an accelerator-based facility for the boron neutron capture therapy. The energy of the incident proton and the arrangement of the moderator assemblies are optimized. The beam current and the accelerating voltage are determined so that the accelerator power becomes minimum. The proposed facility is equipped with a 2.5 MeV proton accelerator of 10-25 mA, a lithium target, and a heavy water moderator contained in an aluminum tank. Each of these equipment is feasible, if proper R and D works have been done. Our new design requires the beam power of less than a hundred kW for the accelerator, although that of our previous design was 1 MW. The reduction of the beam power makes the cooling system for the target much simpler. The essential issues for realization of this concept are long-life lithium targets under high heat flux and high current proton accelerators with average currents of more than 10 mA. It is necessary for the reasonable design of a small-sized and low cost facility to get good accuracy nuclear reaction data. Especially, the latest Li/Be(p, n) neutron yield data in a range of threshold energy - few MeV are required for exact evaluation of neutron energy spectrum used therapy. And damage data by low energy proton beam are also important to evaluate integrity of target material. (author)

Possible application of boron neutron capture therapy to canine osteosarcoma

International Nuclear Information System (INIS)

Takeuchi, Akira

1985-01-01

Possibility for successful treatment of canine osteosarcoma by boron neutron capture therapy (BNCT) was demonstrated based upon an uptake study of the boron compound and an experimental treatment by BNCT. In the up take study following intravenous administration of Na 2 B 12 H 11 SH, satisfactorily higher boron concentration with some variation between tumors is likely to be obtained 12 hours after the administration, together with significantly lower boron levels in blood and bone. Based upon these results, osteosarcoma of a mongrel dog was successfully treated by BNCT. The tumor received approximately 3800 rads with single neutron irradiation (approximately 1.4 x 10 13 n./cm 2 ) about 12 hours after intravenous infusion of Na 2 B 12 H 11 SH of 96 % enriched 10 B in the ratio of 50 mg 10 B/kg. Clinical and radiographical improvements were remarkable and no neoplastic cell was found in any part of the original neoplastic lesion and its surrounding tissue at the time of autopsy after 30 days. (author)

Implantation of boron in silicon

International Nuclear Information System (INIS)

Hofker, W.K.

1975-01-01

The distribution versus depth of boron implanted in silicon and the corresponding electrical activity obtained after annealing are studied. The boron distributions are measured by secondary-ion mass spectrometry. Boron distributions implanted at energies in the range from 30 keV to 800 keV in amorphous and polycrystalline silicon are analysed. Moments of these distributions are determined by a curve-fitting programme and compared with moments calculated by Winterbon. Boron distributions obtained by implantations along a dense crystallographic direction in monocrystalline silicon are found to have penetrating tails. After investigation of some possible mechanisms of tail formation it is concluded that the tails are due to channelling. It was found that the behaviour of boron during annealing is determined by the properties of three boron fractions consisting of precipitated boron, interstitial boron and substitutional boron. The electrical activity of the boron versus depth is found to be consistent with the three boron fractions. A peculiar redistribution of boron is found which is induced by the implantation of a high dose of heavy ions and subsequent annealing. Different mechanisms which may cause the observed effects, such as thermal diffusion which is influenced by lattice strain and damage, are discussed. (Auth.)

Electrochemical characterization of doped diamond-coated carbon fibers at different boron concentrations

Energy Technology Data Exchange (ETDEWEB)

Almeida, E.C. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil)]. E-mail: erica@las.inpe.br; Diniz, A.V. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Trava-Airoldi, V.J. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Ferreira, N.G. [CTA-Divisao de Materiais, Sao Jose dos Campos, SP 12228-904 (Brazil)

2005-08-01

Doped diamond films have been deposited on carbon fibers (felt) obtained from polyacrylonitrile at different levels of boron doping. For a successful coating of the fibers, an ultrasonic pretreatment in a bath of diamond powder dissolved in hexane was required. Films were grown on both sample sides, simultaneously, by hot filament-assisted chemical vapour deposition technique at 750 deg. C from a 0.5% H{sub 2}/CH{sub 4} mixture at a total pressure of 6.5 x 10{sup 3} Pa. Boron was obtained from H{sub 2} forced to pass through a bubbler containing B{sub 2}O{sub 3} dissolved in methanol. The doping level studied corresponds to films with acceptor concentrations in the range of 6.5 x 10{sup 18} to 1.5 x 10{sup 21} cm{sup -} {sup 3}, obtained from Mott-Schottky plots. Scanning electron microscopy analyses evidenced fibers totally covered with high quality polycrystalline boron-doped diamond film, also confirmed by Raman spectroscopy spectra. Diamond electrodes grown on carbon fibers demonstrated similar electrochemical behavior obtained from films on Si substrate, for ferri/ferrocyanide redox couple as a function of boron content. The boron content influences electrochemical surface area. A lower boron concentration provides a higher growth rate that results in a higher surface area.

Beam Transport Devices for the 10 kW IR Free Electron Laser

International Nuclear Information System (INIS)

Lawrence Dillon-Townes; Michael Bevins; David Kashy; Stephanie Slachtouski; Ronald Lassiter; George Neil; Michelle Shinn; Joseph Gubeli; Christopher Behre; David Douglas; David W. Waldman; George Biallas; Lawrence Munk; Christopher Gould

2005-01-01

Beam transport components for the 10kW IR Free Electron Laser (FEL) at Thomas Jefferson National Accelerator Facility (Jefferson Lab) were designed to manage (1) electron beam transport and (2) photon beam transport. An overview of the components will be presented in this paper. The electron beam transport components were designed to address RF heating, maintain an accelerator transport vacuum of 1 x 10 -8 torr, deliver photons to the optical cavity, and provide 50 kW of beam absorption during the energy recovery process. The components presented include a novel shielded bellows, a novel zero length beam clipper, a one decade differential pumping station with a 7.62 cm (3.0 inch) aperture, and a 50 kW beam dump. The photon beam transport components were designed to address the management of photons delivered by the accelerator transport. The optical cavity manages the photons and optical transport delivers the 10 kW of laser power to experimental labs. The optical cavity component presented is a unique high reflector vessel and the optical transport component presented is a turning mirror cassette

Design of experiment existing parameter physics for supporting of Boron Neutron Capture Therapy (BNCT) method a t the piercing radial beam port of Kartini research reactor

International Nuclear Information System (INIS)

Indry Septiana Novitasari; Yosaphat Sumardi; Widarto

2014-01-01

The experiment existing parameters physics for supporting of in vivo and in vitro test facility of Boron Neutron Capture Therapy (BNCT) preliminary study at the piercing radial beam port has been done. The existing experiments is needed for determining that the parameter physics is fulfill the BNCT method requirement. To realize the existing experiment have been done by design analysis, methodology, calculation method and some procedure related with radiation safety analysis and environment. Preparation for existing experiment physics such as foil detector of Gold (Au) should be irradiated for 30 minute, irradiation instrument and procedure related with the experiment for radiation safety. (author)

High sensitivity boron quantification in bulk silicon using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction

Energy Technology Data Exchange (ETDEWEB)

Moro, Marcos V.; Silva, Tiago F. da; Added, Nemitala; Rizutto, Marcia A.; Tabacniks, Manfredo H. [Instituto de Fisica da Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil); Neira, John B.; Neto, Joao B. F. [Institute of Research Tecnology, Cidade Universitaria, SP, 05508-091 (Brazil)

2013-05-06

There is a great need to quantify sub-ppm levels of boron in bulk silicon. There are several methods to analyze B in Si: Nuclear Reaction Analysis using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be reaction exhibits a quantification limit of some hundreds ppm of B in Si. Heavy Ion Elastic Recoil Detection Analysis offers a detection limit of 5 to 10 at. ppm. Secondary Ion Mass Spectrometry is the method of choice of the semiconductor industry for the analysis of B in Si. This work verifies the use of NRA to quantify B in Si, and the corresponding detection limits. Proton beam with 1.6 up to 2.6 MeV was used to obtain the cross-section of the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction at 170 Degree-Sign scattering angle. The results show good agreementwith literature indicating that the quantification of boron in silicon can be achieved at 100 ppm level (high sensitivity) at LAMFI-IFUSP with about 16% uncertainty. Increasing the detection solid angle and the collected beam charge, can reduce the detection limit to less than 100 ppm meeting present technological needs.

Boron exposure through drinking water during pregnancy and birth size.

Science.gov (United States)

Igra, Annachiara Malin; Harari, Florencia; Lu, Ying; Casimiro, Esperanza; Vahter, Marie

2016-10-01

Boron is a metalloid found at highly varying concentrations in soil and water. Experimental data indicate that boron is a developmental toxicant, but the few human toxicity data available concern mostly male reproduction. To evaluate potential effects of boron exposure through drinking water on pregnancy outcomes. In a mother-child cohort in northern Argentina (n=194), 1-3 samples of serum, whole blood and urine were collected per woman during pregnancy and analyzed for boron and other elements to which exposure occurred, using inductively coupled plasma mass spectrometry. Infant weight, length and head circumference were measured at birth. Drinking water boron ranged 377-10,929μg/L. The serum boron concentrations during pregnancy ranged 0.73-605μg/L (median 133μg/L) and correlated strongly with whole-blood and urinary boron, and, to a lesser extent, with water boron. In multivariable-adjusted linear spline regression analysis (non-linear association), we found that serum boron concentrations above 80μg/L were inversely associated with birth length (B-0.69cm, 95% CI -1.4; -0.024, p=0.043, per 100μg/L increase in serum boron). The impact of boron appeared stronger when we restricted the exposure to the third trimester, when the serum boron concentrations were the highest (0.73-447μg/L). An increase in serum boron of 100μg/L in the third trimester corresponded to 0.9cm shorter and 120g lighter newborns (p=0.001 and 0.021, respectively). Considering that elevated boron concentrations in drinking water are common in many areas of the world, although more screening is warranted, our novel findings warrant additional research on early-life exposure in other populations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ammonium-tungstate-promoted growth of boron nitride nanotubes

Science.gov (United States)

E, Songfeng; Li, Chaowei; Li, Taotao; Geng, Renjie; Li, Qiulong; Lu, Weibang; Yao, Yagang

2018-05-01

Ammonium tungstate ((NH4)10W12O41 · xH2O) is a kind of oxygen-containing ammonium salt. The following study proves that it can be successfully used as a metal oxide alternative to produce boron oxide (B2O2) by oxidizing boron (B) in a traditional boron oxide chemical vapor deposition (BOCVD) process. This special oxidant promotes the simplistic fabrication of boron nitride nanotubes (BNNTs) in a conventional horizontal tube furnace, an outcome which may have resulted from its strong oxidizability. The experimental results demonstrate that the mole ratio of B and (NH4)10W12O41 · xH2O is a key parameter in determining the formation, quality and quantity of BNNTs when stainless steel is employed as a catalyst. We also found that Mg(NO3)2 and MgO nanoparticles (NPs) can be used as catalysts to grow BNNTs with the same precursor. The BNNTs obtained from the Mg(NO3)2 catalyst were straighter than those obtained from the MgO NP catalyst. This could have been due to the different physical forms of the catalysts that were used.

Design of an irradiation facility with thermal, epithermal and fast neutron beams

International Nuclear Information System (INIS)

Pfister, G.; Bernnat, W.; Seidel, R.; Schatz, A.K.; Wagner, F.M.; Waschkowski, W.; Schraube, H.

1992-01-01

The main features of a neutron irradiation facility to be installed at the planned research reactor FRM-II are presented. In addition to the operational possibilities of the existing facility at the reactor FRM-I, the new facility will produce quasi-monoenergetic neutron fields and a neutron beam in the keV region whose spectrum can be modified by application of suitable filters and scatterers. For this beam, which is well suited for boron capture therapy, calculated boron reaction rates inside a phantom and an experimental verification of the calculations at the existing facility are presented. (orig.) [de

Proceedings of workshop on 'boron chemistry and boron neutron capture therapy'

International Nuclear Information System (INIS)

Kitaoka, Yoshinori

1993-09-01

This volume contains the proceedings of the 5th Workshop on 'the Boron Chemistry and Boron Neutron Capture Therapy' held on February 22 in 1993. The solubility of the boron carrier play an important role in the BNCT. New water-soluble p-boronophenylalanine derivatives are synthesized and their biological activities are investigated (Chap. 2 and 3). Some chemical problems on the BNCT were discussed, and the complex formation reaction of hydroxylboryl compounds were studied by the paper electrophoresis (Chap. 4). The results of the medical investigation on the BNCT using BSH compounds are shown in Chap. 5. Syntheses of o- and m-boronophenylalanine were done and their optical resolution was tried (Chap. 6). The complex formation reaction of p-boronophenylalanine (BPA) with L-DOPA and the oxidation reaction of the analogs are found in Chap. 7. The pka of BPA were determined by the isotachophoresis (Chap. 8). The chemical nature of dihydroxyboryl compounds were investigated by an infrared spectroscopy and electrophoresis (Chap. 9). New synthetic methods of BPA and p-boronophenylserine using ester of isocyanoacetic acid are described in Chap. 10. The induction of chromosomal aberations by neutron capture reaction are discussed from a point of the biological view. The a of the presented papers are indexed individually. (J.P.N.)

Application of drug delivery system to boron neutron capture therapy for cancer.

Science.gov (United States)

Yanagië, Hironobu; Ogata, Aya; Sugiyama, Hirotaka; Eriguchi, Masazumi; Takamoto, Shinichi; Takahashi, Hiroyuki

2008-04-01

Tumor cell destruction in boron neutron capture therapy (BNCT) is due to the nuclear reaction between (10)B and thermal neutrons ((10)B + (1)n --> (7)Li + (4)He (alpha) + 2.31 MeV (93.7 %)/2.79 MeV (6.3 %)). The resulting lithium ions and alphaparticles are high linear energy transfer (LET) particles which give a high biological effect. Their short range in tissue (5 - 9 mum) restricts radiation damage to those cells in which boron atoms are located at the time of neutron irradiation. BNCT has been applied clinically for the treatment of malignant brain tumors, malignant melanoma, head and neck cancer and hepatoma. Sodium mercaptoundecahydro-dodecaborate (Na(2)(10)B(12)H(11)SH: BSH) and borono-phenylalanine ((10)BPA) are currently being used in clinical treatments. These low molecule compounds are easily cleared from cancer cells and blood, so high accumulation and selective delivery of boron compounds into tumor tissues and cancer cells are most important to achieve effective BNCT and to avoid damage to adjacent healthy cells. In order to achieve the selective delivery of boron atoms to cancer cells, a drug delivery system (DDS) is an attractive intelligent technology for targeting and controlled release of drugs. We performed literature searches related to boron delivery systems in vitro and in vivo. We describe several DDS technologies for boron delivery to cancer tissues and cancer cells from the past to current status. We are convinced that it will be possible to use liposomes, monoclonal antibodies and WOW emulsions as boron delivery systems for BNCT clinically in accordance with the preparation of good commercial product (GCP) grade materials.

The effect of the boron source composition ratio on the adsorption performance of hexagonal boron nitride without a template

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ning, E-mail: zhangning5832@163.com; Zhang, Tong; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Cui, Xingyu

2015-08-01

An inexpensive boric acid (H{sub 3}BO{sub 3}) and borax (Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O) mix was used as a source of boron with different composition ratios, and urea was used as a nitrogen source, in flowing ammonia atmosphere, for the preparation of hexagonal boron nitride (h-BN) with different micro-morphologies. Under a certain synthesis process, the effects of the molar ratio of borax and boric acid (or simply the boron source composition ratio for short) on the phase composition of the sample were studied; the work also explored the effect of boron source composition ratio on the micro-morphology, adsorption desorption isotherm and specific surface area of the h-BN powder. The main purpose of this work was to determine the optimum composition ratio of preparing spherical mesoporous h-BN and ensure that the micro-mechanism underpinning the formation of spherical mesoporous h-BN was understood. The results showed that at the optimum boron source composition ratio of 1:1, globular mesoporous spheres with a diameter of approximately 600–800 nm could be obtained with the highest pore volume and specific surface area (230.2 m{sup 2}/g). - Graphical abstract: Display Omitted - Highlights: • Spherical h-BN was synthesized by controlling the boron source composition ratio. • Without extra spherical template, solid Na{sub 2}O was equal to a spherical template. • At boron source composition ratio of 1:1, h-BN had best adsorption performance.

Analytical dosimetry for spontaneous tumor dogs receiving boron neutron capture therapy

International Nuclear Information System (INIS)

Wheeler, F.J.; Atkinson, C.A.; Gavin, P.R.

1992-01-01

The dog irradiation project of the Power Burst Facility/Boron Neutron Capture Therapy (PBF/BNCT) Program is administered by Washington State University (WSU) with analytical and physical dosimetry provided by the Idaho National Engineering Laboratory (INEL). One subtask of this project includes BNCT safety studies for dogs with spontaneously-occurring brain tumors. The boron compound (Na 2 B 12 H 11 SH or BSH) was administered and single irradiations performed using the epithermal-neutron beam at the Brookhaven Medical Research Reactor (BMRR). The main goal of the study was not to provide therapy, but to determine tumorcidal effect while administering a subtolerance dose to healthy tissue. Irradiation times were based on delivery of 19 Gy peak physical dose to the blood

performance calculations of gadolinium oxide and boron nitride coated fuel

International Nuclear Information System (INIS)

Tanker, E.; Uslu, I.; Disbudak, H.; Guenduez, G.

1997-01-01

A comparative study was performed on the behaviour of natural uranium dioxide-gadolinium oxide mixture fuel and boron nitride coated low enriched fuel in a pressurized water reactor. A fuel element containing one burnable poison fuel pins was modeled with the computer code WIMS, and burn-up dependent critically, fissile isotope inventory and two dimensional power distribution were obtained. Calculations were performed for burnable poison fuels containing 5% and 10% gadolinium oxide and for those coated with 1μ,5μ and 10μ of boron nitride. Boron nitride coating was found superior to gadolinium oxide on account of its smoother criticality curve, lower power peaks and insignificant change in fissile isotope content

Dose distribution and clinical response of glioblastoma treated with boron neutron capture therapy

Energy Technology Data Exchange (ETDEWEB)

Matsuda, M. [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan)], E-mail: mhide-m@gk9.so-net.ne.jp; Yamamoto, T. [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan); Kumada, H. [Japan Atomic Energy Agency, Shirakatashirane 2-4, Tokai (Japan); Nakai, K.; Shirakawa, M.; Tsurubuchi, T.; Matsumura, A. [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan)

2009-07-15

The dose distribution and failure pattern after treatment with the external beam boron neutron capture therapy (BNCT) protocol were retrospectively analyzed. BSH (5 g/body) and BPA (250 mg/kg) based BNCT was performed in eight patients with newly diagnosed glioblastoma. The gross tumor volume (GTV) and clinical target volume (CTV)-1 were defined as the residual gadolinium-enhancing volume. CTV-2 and CTV-3 were defined as GTV plus a margin of 2 and 3 cm, respectively. As additional photon irradiation, a total X-ray dose of 30 Gy was given to the T2 high intensity area on MRI. Five of the eight patients were alive at analysis for a mean follow-up time of 20.3 months. The post-operative median survival time of the eight patients was 27.9 months (95% CI=21.0-34.8). The minimum tumor dose of GTV, CTV-2, and CTV-3 averaged 29.8{+-}9.9, 15.1{+-}5.4, and 12.4{+-}2.9 Gy, respectively. The minimum tumor non-boron dose of GTV, CTV-2, and CTV-3 averaged 2.0{+-}0.5, 1.3{+-}0.3, and 1.1{+-}0.2 Gy, respectively. The maximum normal brain dose, skin dose, and average brain dose were 11.4{+-}1.5, 9.6{+-}1.4, and 3.1{+-}0.4 Gy, respectively. The mean minimum dose at the failure site in cases of in-field recurrence (IR) and out-field recurrence (OR) was 26.3{+-}16.7 and 14.9 GyEq, respectively. The calculated doses at the failure site were at least equal to the tumor control doses which were previously reported. We speculate that the failure pattern was related to an inadequate distribution of boron-10. Further improvement of the microdistribution of boron compounds is expected, and may improve the tumor control by BNCT.

Boron isotope separation by ion exchange chromatography using weakly basic anion exchange resin

International Nuclear Information System (INIS)

Sakuma, Yoichi; Aida, Masao; Okamoto, Makoto; Kakihana, Hidetake

1980-01-01

Isotopic plateau displacement chromatography, a useful method for isotope separation is presented. The boric acid band formed in a column of weakly basic anion exchange resin Diaion WA21 can be eluted with pure water. In order to obtain good accumulation of the isotope effect, a series of experiments with different migration length were carried out. The boron-10 enriched part of the boric acid absorbed band was always preceded by the isotopic plateau part, in which the atomic fraction of boron-10 was maintained at its original value. The atomic fraction of boron-10 at the end of the chromatogram increased with migration length, and in the case of 256-m migration, boron-10 was enriched from its original atomic fraction of 19.84 to 91.00%, the separation factor S being constant irrespective of migration length: S = 1.0100 +- 0.0005. (author)

Model for the boron-doping dependence of the critical temperature of superconducting boron-doped diamond

Czech Academy of Sciences Publication Activity Database

Šopík, Břetislav

2009-01-01

Roč. 11, č. 10 (2009), 103026/1-103026/10 ISSN 1367-2630 R&D Projects: GA AV ČR IAA100100712 Grant - others:GAČR(CZ) GA202/07/0597 Institutional research plan: CEZ:AV0Z10100521 Keywords : superconductivity * boron-doped diamond Subject RIV: BE - Theoretical Physics Impact factor: 3.312, year: 2009

Evaluation of plasma disruption simulating short pulse laser irradiation experiments on boronated graphites and CFCs [carbon fibre composites

International Nuclear Information System (INIS)

Stad, R.C.L. van der; Klippel, H.T.; Kraaij, G.J.

1992-12-01

New experimental and numerical results from disruption heat flux simulations in the millisecond range with laser beams are discussed. For a number of graphites, boronated graphites and carbon fibre composites, the effective enthalpy of ablation is determined as 30 ± 3 MJ/kg, using laser pulses of about -.3 ms. The numerical results predict the experimental results rather well. No effect of boron doping on the ablation enthalpy is found. (author). 9 refs., 4 figs., 1 tab

Depth resolved investigations of boron implanted silicon

Science.gov (United States)

Sztucki, M.; Metzger, T. H.; Milita, S.; Berberich, F.; Schell, N.; Rouvière, J. L.; Patel, J.

2003-01-01

We have studied the depth distribution and structure of defects in boron implanted silicon (0 0 1). Silicon wafers were implanted with a boron dose of 6×10 15 ions/cm -2 at 32 keV and went through different annealing treatments. Using diffuse X-ray scattering at grazing incidence and exit angles we are able to distinguish between different kinds of defects (point defect clusters and extrinsic stacking faults on {1 1 1} planes) and to determine their depth distribution as a function of the thermal budget. Cross-section transmission electron microscopy was used to gain complementary information. In addition we have determined the strain distribution caused by the boron implantation as a function of depth from rocking curve measurements.

A sensitivity study on neutron flux variation due to 10B concentration in dose calculation for BNCT

International Nuclear Information System (INIS)

Jung, Sang Hoon

2006-02-01

The effects of inclusion of 10 B concentration on neutron flux and dose in dose calculation were studied. In order to provide the quantitative effects of inclusion of 10 B concentrations on depressions of neutron and photon flux and dose, the fluxes and doses with voxel head phantoms for various 10 B concentrations homogeneously distributed were calculated by using MCNPX simulations. A lithium target system and beam shaping assembly, which have been developed at the Hanyang University, were used as epithermal neutron beam. The calculation results show that the neutron flux at the center of the head phantom decreases by approximately 5.4% per 10 ppm of 10 B concentration in comparison with the neutron flux in the case of boron-free. It was also observed that the tissue dose at the center of the head phantom is depressed by approximately 4.7% per 10 ppm of the 10 B concentration and the tumor dose by approximately 5.3% per 10 ppm. According to depth of tumors, it was observed that the depressions of the doses in the tumors are ranged in 3.7 ∼ 9.2%. The dose calculations in the case of boron-free show that it is overestimated in comparison with the dose calculations in the cases of the inclusion of 10 B concentrations for the normal tissue and the tumors. Therefore, in dose calculation for BNCT, the depressions of neutron flux and dose should be considered. The results in this study are available to setting up the depression ratios which can be used for converting neutron and gamma fluxes and doses in phantom with boron free into the fluxes and doses in phantom with inclusion of 10 B concentrations in treatment. It is expected that the depression ratios is practicable to dose evaluation for BNCT

Spectrophotometric determination of boron by solvent extraction with 2-hydroxy-2-methylbutyric acid and malachite green

International Nuclear Information System (INIS)

Sato, Shigeya; Uchikawa, Sumio

1984-01-01

A very simple and sensitive method for the spectrophotometric determination of boron was developed. Boron was found to react with 2-hydroxy-2-methylbutyric acid in weak acidic aqueous solution at room temperature to form a complex anion which can be extracted into chlorobenzene with malachite green in a single extraction; boron is determined indirectly by measuring the absorbance of malachite green in the extract at 629 nm. The calibration graph is linear over the range (7.50 x 10 -7 - 2.00 x 10 -5 ) mol dm -3 boron; the apparent molar absorptivity is 6.50 x 10 4 dm 3 mol -1 cm -1 . The method is applied to the determination of micro amounts of boron in natural waters with satisfactory results. (author)

Ultrastructural changes in tumor cells following boron neutron capture therapy

International Nuclear Information System (INIS)

Barkla, D.H.; Brown, J.K.; Meriaty, H.; Allen, B.J.

1992-01-01

In a previous study the authors reported on morphological changes in two human melanoma cell lines treated with 10 B-phenylalanine(BPA) and Boron Neutron Capture Therapy(BNCT). The present study describes morphological changes in melanoma and glioma cell lines treated with boron-tetraphenyl porphyrin(BTPP) and BNCT. Porphyrin compounds are selectively taken up by tumor cells and have been used clinically in phototherapy treatment of cancer patients. Boronated porphyrins show good potential as therapeutic agents in BNCT treatment of human cancer patients

Selective boron accumulation in human ocular melanoma by 10B1-para-boronophenylalanine administration for neutron capture therapy

International Nuclear Information System (INIS)

Wadabayashi, Nobutoshi; Ichihashi, Masamitsu; Honda, Chihiro; Mishima, Yutaka.

1994-01-01

Malignant melanoma occurs not only in the skin but also in ocular tissues. Ocular melanoma located superficially as in conjunctiva can be treated successfully by BNCT. In the present study, we investigated 10 B dynamics in ocular melanoma and the surrounding normal tissues, to evaluate the possibility of applying BNCT to ocular melanoma. In three ocular melanoma patients, 10 B concentration in melanoma after administration of 10 B-BPA by oral or drip infusion ranged from 10.4 to 21.5 ppm. The boron concentrations in lens and vitreous body were lower than blood level, whereas higher than blood in sclera and palpebral skin. These results suggest that we can treat such a superficial melanoma lesions as conjunctival melanoma by BNCT using 10 B 1 -BPA. (author)

Boron Neutron Capture Therapy in the Treatment of Recurrent Laryngeal Cancer

Energy Technology Data Exchange (ETDEWEB)

Haapaniemi, Aaro, E-mail: aaro.haapaniemi@hus.fi [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Kankaanranta, Leena [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Saat, Riste [Department of Radiology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Koivunoro, Hanna; Saarilahti, Kauko [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Mäkitie, Antti; Atula, Timo [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Joensuu, Heikki [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland)

2016-05-01

Purpose: To investigate the safety and efficacy of boron neutron capture therapy (BNCT) as a larynx-preserving treatment option for patients with recurrent laryngeal cancer. Methods and Materials: Six patients with locally recurrent squamous cell laryngeal carcinoma and 3 patients with persistent laryngeal cancer after prior treatment were treated with BNCT at the FiR1 facility (Espoo, Finland) in 2006 to 2012. The patients had received prior radiation therapy with or without concomitant chemotherapy to a cumulative median dose of 66 Gy. The median tumor diameter was 2.9 cm (range, 1.4-10.9 cm) before BNCT. Boron neutron capture therapy was offered on a compassionate basis to patients who either refused laryngectomy (n=7) or had an inoperable tumor (n=2). Boronophenylalanine-fructose (400 mg/kg) was used as the boron carrier and was infused over 2 hours intravenously before neutron irradiation. Results: Six patients received BNCT once and 3 twice. The estimated average gross tumor volume dose ranged from 22 to 38 Gy (W) (mean; 29 Gy [W]). Six of the 8 evaluable patients responded to BNCT; 2 achieved complete and 4 partial response. One patient died early and was not evaluable for response. Most common side effects were stomatitis, fatigue, and oral pain. No life-threatening or grade 4 toxicity was observed. The median time to progression within the target volume was 6.6 months, and the median overall survival time 13.3 months after BNCT. One patient with complete response is alive and disease-free with a functioning larynx 60 months after BNCT. Conclusions: Boron neutron capture therapy given after prior external beam radiation therapy is well tolerated. Most patients responded to BNCT, but long-term survival with larynx preservation was infrequent owing to cancer progression. Selected patients with recurrent laryngeal cancer may benefit from BNCT.

Surface modification of the hard metal tungsten carbide-cobalt by boron ion implantation; Oberflaechenmodifikation des Hartmetalls Wolframkarbid-Kobalt durch Bor-Ionenimplantation

Energy Technology Data Exchange (ETDEWEB)

Mrotchek, I.

2007-09-07

In the present thesis ion beam implantation of boron is studied as method for the increasement of the hardness and for the improvement of the operational characteristics of cutting tools on the tungsten carbide-cobalt base. For the boron implantation with 40 keV energy and {approx}5.10{sup 17} ions/cm{sup 2} fluence following topics were shown: The incoerporation of boron leads to a deformation and remaining strain of the WC lattice, which possesses different stregth in the different directions of the elementary cell. The maximum of the deformation is reached at an implantation temperature of 450 C. The segregation of the new phases CoWB and Co{sub 3}W was detected at 900 C implantation temperature. At lower temperatures now new phases were found. The tribological characteristics of WC-Co are improved. Hereby the maxiaml effect was measured for implantation temperatures from 450 C to 700 C: Improvement of the microhardness by the factor 2..2.5, improvement of the wear resistance by the factor 4. The tribological effects extend to larger depths than the penetration depth of the boron implantation profile. The detected property improvements of the hard metal H3 show the possibility of a practical application of boron ion implantation in industry. The effects essential for a wer decreasement are a hardening of the carbide phase by deformation of the lattice, a hardening of the cobalt binding material and the phase boundaries because of the formation of a solid solution of the implanted boron atoms in Co and by this a blocking of the dislocation movement and the rupture spreading under load.

Recycling behaviour during long pulse discharges after ICRF boronization in the HT-7 tokamak

International Nuclear Information System (INIS)

Huang, J.; Wan, B.N.; Li, J.G.; Gong, X.Z.; Zhang, X.D.; Wu, Z.W.; Zhou, Q.

2006-01-01

The evolution of recycling behaviour has been investigated during long pulse discharges in the HT-7 tokamak after ICRF boronization (C 2 B 10 H 12 ) using the H/(H+D) ratio and the edge recycling coefficient R. After boronization, impurity reduction is observed, attributed to the fresh boron film, but the recycling coefficient can exceed unity due to a large amount of hydrogen absorbed in the film, leading to an uncontrollable density rise and discharge termination. When the H/(H+D) ratio was reduced to less than 25%, the electron density was easily controlled. The longest discharge, up to 240 s with central electron temperature T e (0) of about 1.0 keV and central electron density n e (0) of 0.8 x 10 19 m -3 , was achieved following boronization. After many discharges the effectiveness of boron film was weakened, and the density rise was correlated with an increase in both carbon and oxygen radiation which limited the duration of long pulse discharges

"Sequential” Boron Neutron Capture Therapy (BNCT): A Novel Approach to BNCT for the Treatment of Oral Cancer in the Hamster Cheek Pouch Model

Energy Technology Data Exchange (ETDEWEB)

Ana J. Molinari; Andrea Monti Hughes; Elisa M. Heber; Marcela A. Garabalino; Veronica A. Trivillin; Amanda E. Schwint; Emiliano C. C. Pozzi; Maria E. Itoiz; Silvia I. Thorp; Romina F. Aromando; David W. Nigg; Jorge Quintana; Gustavo A. Santa Cruz

2011-04-01

Boron Neutron Capture Therapy (BNCT) is a binary treatment modality that involves the selective accumulation of 10B carriers in tumors followed by irradiation with a thermal or epithermal neutron beam. The minor abundance stable isotope of boron, 10B, interacts with low energy (thermal) neutrons to produce high linear energy transfer (LET) a-particles and 7Li ions. These disintegration products are known to have a high relative biological effectiveness (RBE). Their short range (<10 {micro}m) would limit the damage to cells containing 10B (1,2). Thus, BNCT would target tumor tissue selectively, sparing normal tissue. Clinical trials of BNCT for the treatment of glioblastoma multiforme and/or melanoma and, more recently, head and neck tumors and liver metastases, using boronophenylalanine (BPA) or sodium mercaptoundecahydrododecaborane (BSH) as the 10B carriers, have been performed or are underway in Argentina, Japan, the US and Europe (e.g. 3-8). To date, the clinical results have shown a potential, albeit inconclusive, therapeutic advantage for this technique. Contributory translational studies have been carried out employing a variety of experimental models based on the implantation of tumor cells in normal tissue (e.g. 5).

Development of L-band, 10MW multi beam klystron

International Nuclear Information System (INIS)

Irikura, M.; Miyake, S.; Yano, A.; Kazakov, S.; Larionov, A.; Teryaev, V.; Chin, Y.H.

2004-01-01

A 10-MW, L-band multi beam klystron (MBK) for TESLA linear collider and TESLA XFEL has been under development at Toshiba Electron Tubes and Devices Co., Ltd. (TETD) in collaboration with KEK. The TESLA requires pulsed klystrons capable of 10 MW output power at 1300 MHz with 1.5 ms pulse length and a repetition rate of 10 pps. The MBK with 6 low-perveance beams in parallel enables us to operate at lower cathode voltage with higher efficiency. The design work has been accomplished and the fabrication is under way. We are going to start conditioning and testing of prototype no.0 in the middle of July 2004. The design overview will be presented. (author)

Lattice dynamics of α boron and of boron carbide

International Nuclear Information System (INIS)

Vast, N.

1999-01-01

The atomic structure and the lattice dynamics of α boron and of B 4 C boron carbide have been studied by Density Functional Theory (D.F.T.) and Density Functional Perturbation Theory (D.F.P.T.). The bulk moduli of the unit-cell and of the icosahedron have been investigated, and the equation of state at zero temperature has been determined. In α boron, Raman diffusion and infrared absorption have been studied under pressure, and the theoretical and experimental Grueneisen coefficients have been compared. In boron carbide, inspection of the theoretical and experimental vibrational spectra has led to the determination of the atomic structure of B 4 C. Finally, the effects of isotopic disorder have been modeled by an exact method beyond the mean-field approximation, and the effects onto the Raman lines has been investigated. The method has been applied to isotopic alloys of diamond and germanium. (author)

Research of boron conversion coating in neutron detector with boron deposited GEM

International Nuclear Information System (INIS)

Ye Di; Sun Zhijia; Zhou Jianrong; Wang Yanfeng; Yang Guian; Xu Hong; Chen Yuanbai; Xiao Yu; Diao Xungang

2014-01-01

GEM is a flourishing new gas detector and nowadays its technology become more mature. It has outstanding properties, such as excellent position resolution, high counting rate, radiation resistance, simple and flexible signal readout, can be large-area detector, wide application range. Detector with boron deposited GEM uses multilayer GEM with deposited boron film as neutron conversion carrier which reads out the information of neutron shot from the readout electrode with gas amplification from every GEM layer. The detector is high performance which can meet the demands of neutron detector of a new generation. Boron deposited neutron conversion electrode with boron deposited cathode and GEM included is the core part of the detector. As boron is a high-melting-point metalloid (> 2 000 ℃), electroplating and thermal evaporation are inappropriate ways. So finding a way to deposit boron on electrode which can meet the demands become a key technology in the development of neutron detector with boron deposited GEM. Compared with evaporation, sputtering has features such as low deposition temperature, high film purity, nice adhesive, thus is appropriate for our research. Magnetron sputtering is a improved way of sputtering which can get lower sputtering air pressure and higher target voltage, so that we can get better films. Through deposit process, the research uses magnetron sputtering to deposit pure boron film on copper electrode and GEM film. This method can get high quality, nice adhere, high purity, controllable uniformity, low cost film with high speed film formation. (authors)

Boron neutron capture therapy for malignant brain tumor in Japan

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Yoshinobu [National Kagawa Children`s Hospital, Takamatsu, Kagawa (Japan)

1998-03-01

Since 1968, we have treated 149 patients and performed boron-neutron capture therapy (BNCT) on 164 occasions using 5 reactors in Japan. There were 64 patients with glioblastoma, 39 patients with anaplastic astrocytoma and 17 patients with low grade astrocytoma (grade 1 or 2). There were 30 patients with other types of tumor. The overall response rate in the glioma patients was 64%. Seven patients (12%) of glioblastoma, 22 patients (56%) of anaplastic astrocytoma and 8 patients (62%) of low grade astrocytoma lived more than 2 years Median survival time of glioblastoma was 640 days. Median survival times of patients with anaplastic astrocytoma was 1811 days, and 1669 days in low grade astrocytoma. Six patients (5 glioblastoma and one anaplastic astrocytoma) died within 90 days after BNCT. Six patients lived more than 10 years. Histological grading, age of the patients, neutron fluence at the target point and target depth or size of the tumor were proved to be important factors. BNCT is an effective treatment for malignant brain tumors. We are now became able to radiate the tumor more correctly with a high enough dose of neutron beam even if we use thermal neutron beam. (author)

Numerical simulation of boron injection in a BWR

Energy Technology Data Exchange (ETDEWEB)

Tinoco, Hernan, E-mail: htb@forsmark.vattenfall.s [Forsmarks Kraftgrupp AB, SE-742 03 Osthammar (Sweden); Buchwald, Przemyslaw [Reactor Technology, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Frid, Wiktor, E-mail: wiktor@reactor.sci.kth.s [Reactor Technology, Royal Institute of Technology, SE-100 44 Stockholm (Sweden)

2010-02-15

The present study constitutes a first step to understand the process of boron injection, transport and mixing in a BWR. It consists of transient CFD simulations of boron injection in a model of the downcomer of Forsmark's Unit 3 containing about 6 million elements. The two cases studied are unintentional start of boron injection under normal operation and loss of offsite power with partial ATWS leaving 10% of the core power uncontrolled. The flow conditions of the second case are defined by means of an analysis with RELAP5, assuming boron injection start directly after the first ECCS injection. Recent publications show that meaningful conservative results may be obtained for boron or thermal mixing in PWRs with grids as coarse as that utilized here, provided that higher order discretization schemes are used to minimize numerical diffusion. The obtained results indicate an apparently strong influence of the scenario in the behavior of the injection process. The normal operation simulation shows that virtually all boron solution flows down to the Main Recirculation Pump inlet located directly below the boron inlet nozzle. The loss of offsite power simulation shows initially a spread of the boron solution over the entire sectional area of the lower part of the downcomer filled with colder water. This remaining effect of the ECCS injection lasts until all this water has left the downcomer. Above this region, the boron injection jet develops in a vertical streak, eventually resembling the injection of the normal operation scenario. Due to the initial spread, this boron injection will probably cause larger temporal and spatial concentration variations in the core. In both cases, these variations may cause reactivity transients and fuel damage due to local power escalation. To settle this issue, an analysis using an extended model containing the downcomer, the MRPs and the Lower Plenum will be carried out. Also, the simulation time will be extended to a scale of

Numerical simulation of boron injection in a BWR

International Nuclear Information System (INIS)

Tinoco, Hernan; Buchwald, Przemyslaw; Frid, Wiktor

2010-01-01

The present study constitutes a first step to understand the process of boron injection, transport and mixing in a BWR. It consists of transient CFD simulations of boron injection in a model of the downcomer of Forsmark's Unit 3 containing about 6 million elements. The two cases studied are unintentional start of boron injection under normal operation and loss of offsite power with partial ATWS leaving 10% of the core power uncontrolled. The flow conditions of the second case are defined by means of an analysis with RELAP5, assuming boron injection start directly after the first ECCS injection. Recent publications show that meaningful conservative results may be obtained for boron or thermal mixing in PWRs with grids as coarse as that utilized here, provided that higher order discretization schemes are used to minimize numerical diffusion. The obtained results indicate an apparently strong influence of the scenario in the behavior of the injection process. The normal operation simulation shows that virtually all boron solution flows down to the Main Recirculation Pump inlet located directly below the boron inlet nozzle. The loss of offsite power simulation shows initially a spread of the boron solution over the entire sectional area of the lower part of the downcomer filled with colder water. This remaining effect of the ECCS injection lasts until all this water has left the downcomer. Above this region, the boron injection jet develops in a vertical streak, eventually resembling the injection of the normal operation scenario. Due to the initial spread, this boron injection will probably cause larger temporal and spatial concentration variations in the core. In both cases, these variations may cause reactivity transients and fuel damage due to local power escalation. To settle this issue, an analysis using an extended model containing the downcomer, the MRPs and the Lower Plenum will be carried out. Also, the simulation time will be extended to a scale of several

Electrophoretic deposits of boron on duralumin plates used for measuring neutron flux

International Nuclear Information System (INIS)

Lang, F.M.; Magnier, P.; Finck, C.

1956-01-01

Preparation of boron thin film deposits of around 1 mg per cm 2 on duralumin plates with a diameter of 8 cm. The boron coated plates for ionization chambers were originally prepared at the CEA by pulverization of boron carbides on sodium silicates. This method is not controlling precisely enough the quantity of boron deposit. Thus, an electrophoretic method is considered for a better control of the quantity of boron deposit in the scope of using in the future boron 10 which is costly and rare. The method described by O. Flint is not satisfying enough and a similar electrophoretic process has been developed. Full description of the method is given as well as explanation of the use of dried methanol as solvent, tannin as electrolyte and magnesium chloride to avoid alumina formation. (M.P.)

Use of fluorine-18-BPA PET images and image registration to enhance radiation treatment planning for boron neutron capture therapy

Science.gov (United States)

Khan, Mohammad Khurram

The Monte-Carlo based simulation environment for radiation therapy (SERA) software is used to simulate the dose administered to a patient undergoing boron neutron capture therapy (BNCT). Point sampling of tumor tissue results in an estimate of a uniform boron concentration scaling factor of 3.5. Under conventional treatment protocols, this factor is used to scale the boron component of the dose linearly and homogenously within the tumor and target volumes. The average dose to the tumor cells by such a method could be improved by better methods of quantifying the in-vivo 10B biodistribution. A better method includes radiolabeling para-Boronophenylalanine (p-BPA) with 18F and imaging the pharmaceutical using positron emission tomography (PET). This biodistribution of 18F-BPA can then be used to better predict the average dose delivered to the tumor regions. This work uses registered 18F-BPA PET images to incorporate the in-vivo boron biodistribution within current treatment planning. The registered 18F-BPA PET images are then coupled in a new computer software, PET2MRI.m, to linearly scale the boron component of the dose. A qualititative and quantitative assessment of the dose contours is presented using the two approaches. Tumor volume, tumor axial extent, and target locations are compared between using MRI or PET images to define the tumor volume. In addition, peak-to-normal brain value at tumor axial center is determined for pre and post surgery patients using 18F-BPA PET images. The differences noted between the registered GBM tumor volumes (range: 34.04--136.36%), tumor axial extent (range: 20--150%), and the beam target location (1.27--4.29 cm) are significantly different. The peak-to-normal brain values are also determined at the tumor axial center using the 18F-BPA PET images. The peak-to-normal brain values using the last frame of the pre-surgery study for the GBM patients ranged from 2.05--3.4. For post surgery time weighted PET data, the peak

Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

International Nuclear Information System (INIS)

Nistor, L C; Nistor, S V; Dinca, G; Georgeoni, P; Landuyt, J van; Manfredotti, C; Vittone, E

2002-01-01

High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp 3 bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 pm, 15 mJ m -2 is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond

Chemoradiotherapy of cancer using boronated monoclonal antibodies. Comprehensive progress report, April 1, 1982-October 31, 1984

International Nuclear Information System (INIS)

1984-01-01

Research to develop boron neutron capture for radiotherapy applications is summarized. Work is reported in the following areas: (1) chemical and biochemical research with B 12 H 11 SH 2- ; (2) chemical and protein-binding studies with B 12 H 11 NCO 2- and (CH 3 ) 3 NB 10 H 8 NCO 1- ; (3) effects of neutron irradiation and capture on phytomitogen stimulated lymphocyte blastogenesis; (4) production and characterization of monoclonal antibodies directed against the murine B16 melanoma; (5) reactor description and determination of flux profile; (6) determination of neutron profile; (7) improvement of the neutron beam by the bismuth scatterer method; and (8) in vitro sensitivity of B16 melanoma cells to thermal neutrons and 10 B(n,α) capture. 11 references

Spectrophotometric determination of boron by solvent extraction with 2-hydroxy-2-methylbutyric acid and malachite green

Energy Technology Data Exchange (ETDEWEB)

Sato, Shigeya; Uchikawa, Sumio [Kumamoto Univ. (Japan). Faculty of Education

1984-03-01

A very simple and sensitive method for the spectrophotometric determination of boron was developed. Boron was found to react with 2-hydroxy-2-methylbutyric acid in weak acidic aqueous solution at room temperature to form a complex anion which can be extracted into chlorobenzene with malachite green in a single extraction; boron is determined indirectly by measuring the absorbance of malachite green in the extract at 629 nm. The calibration graph is linear over the range (7.50 x 10/sup -7/ - 2.00 x 10/sup -5/) mol dm/sup -3/ boron; the apparent molar absorptivity is 6.50 x 10/sup 4/ dm/sup 3/ mol/sup -1/ cm/sup -1/. The method is applied to the determination of micro amounts of boron in natural waters with satisfactory results.

EPICS Controlled Collimator for Controlling Beam Sizes in HIPPO

Energy Technology Data Exchange (ETDEWEB)

Napolitano, Arthur Soriano [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogel, Sven C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-08-03

Controlling the beam spot size and shape in a diffraction experiment determines the probed sample volume. The HIPPO - High-Pressure-Preferred Orientation– neutron time-offlight diffractometer is located at the Lujan Neutron Scattering Center in Los Alamos National Laboratories. HIPPO characterizes microstructural parameters, such as phase composition, strains, grain size, or texture, of bulk (cm-sized) samples. In the current setup, the beam spot has a 10 mm diameter. Using a collimator, consisting of two pairs of neutron absorbing boron-nitride slabs, horizontal and vertical dimensions of a rectangular beam spot can be defined. Using the HIPPO robotic sample changer for sample motion, the collimator would enable scanning of e.g. cylindrical samples along the cylinder axis by probing slices of such samples. The project presented here describes implementation of such a collimator, in particular the motion control software. We utilized the EPICS (Experimental Physics Interface and Control System) software interface to integrate the collimator control into the HIPPO instrument control system. Using EPICS, commands are sent to commercial stepper motors that move the beam windows.

Recoil implantation of boron into silicon by high energy silicon ions

Science.gov (United States)

Shao, L.; Lu, X. M.; Wang, X. M.; Rusakova, I.; Mount, G.; Zhang, L. H.; Liu, J. R.; Chu, Wei-Kan

2001-07-01

A recoil implantation technique for shallow junction formation was investigated. After e-gun deposition of a B layer onto Si, 10, 50, or 500 keV Si ion beams were used to introduce surface deposited B atoms into Si by knock-on. It has been shown that recoil implantation with high energy incident ions like 500 keV produces a shallower B profile than lower energy implantation such as 10 keV and 50 keV. This is due to the fact that recoil probability at a given angle is a strong function of the energy of the primary projectile. Boron diffusion was showed to be suppressed in high energy recoil implantation and such suppression became more obvious at higher Si doses. It was suggested that vacancy rich region due to defect imbalance plays the role to suppress B diffusion. Sub-100 nm junction can be formed by this technique with the advantage of high throughput of high energy implanters.

The All Boron Carbide Diode Neutron Detector: Experiment and Modeling Approach

International Nuclear Information System (INIS)

Sabirianov, Ildar F.; Brand, Jennifer I.; Fairchild, Robert W.

2008-01-01

Boron carbide diode detectors, fabricated from two different polytypes of semiconducting boron carbide, will detect neutrons in reasonable agreement with theoretical expectations. The performance of the all boron carbide neutron detector differs, as expected, from devices where a boron rich neutron capture layer is distinct from the diode charge collection region (i.e. a conversion layer solid state detector). Diodes were fabricated from natural abundance boron (20% 10 B and 80% 11 B.) directly on the metal substrates and metal contacts applied to the films as grown. The total boron depth was on the order of 2 microns. This is clearly not a conversion-layer configuration. The diodes were exposed to thermal neutrons generated from a paraffin moderated plutonium-beryllium source in moderated and un-moderated, as well as shielded and unshielded experimental configurations, where the expected energy peaks at at 2.31 MeV and 2.8 MeV were clearly observed, albeit with some incomplete charge collection typical of thinner diode structures. The results are compared with other boron based thin film detectors and literature models. (authors)

Preparation of boron-rich aluminum boride nanoparticles by RF thermal plasma

Energy Technology Data Exchange (ETDEWEB)

Choi, Sooseok [Inha University, Department of Chemical Engineering and Regional Innovation Center for Environmental Technology of Thermal Plasma (Korea, Republic of); Matsuo, Jiro; Cheng, Yingying [Tokyo Institute of Technology, Department of Environmental Chemistry and Engineering (Japan); Watanabe, Takayuki, E-mail: watanabe@chemenv.titech.ac.jp [Kyushu University, Department of Chemical Engineering (Japan)

2013-08-15

Boron-rich compounds of AlB{sub 12} and AlB{sub 10} nanoparticles were synthesized by a radiofrequency thermal plasma. Aluminum and boron raw powders were evaporated in virtue of high enthalpy of the thermal plasma in upstream region, followed by the formation of aluminum boride nanoparticles in the tail region of plasma flame with rapid quenching. A high production rate of aluminum boride was confirmed by the X-ray diffraction measurement in the case of high input power, high boron content in raw material and helium inner gas. Polyhedral nanoparticles of 20.8 nm in mean size were observed by a transmission electron microscope. In the raw powder mixture of aluminum, titanium, and boron, titanium-boride nanoparticles were synthesized preferentially, because the Gibbs free energy for the boridation of titanium is lower than that of aluminum. Since the nucleation temperature of boron is higher than that of aluminum, the condensation of metal monomers onto boron nuclei results in the formation of boron-rich aluminum boride nanoparticles.

Research of accelerator-based neutron source for boron neutron capture therapy

International Nuclear Information System (INIS)

Li Changkai; Ma Yingjie; Tang Xiaobin; Xie Qin; Geng Changran; Chen Da

2013-01-01

Background: 7 Li (p, n) reaction of high neutron yield and low threshold energy has become one of the most important neutron generating reactions for Accelerator-based Boron Neutron Capture Therapy (BNCT). Purpose Focuses on neutron yield and spectrum characteristics of this kind of neutron generating reaction which serves as an accelerator-based neutron source and moderates the high energy neutron beams to meet BNCT requirements. Methods: The yield and energy spectrum of neutrons generated by accelerator-based 7 Li(p, n) reaction with incident proton energy from 1.9 MeV to 3.0 MeV are researched using the Monte Carlo code-MCNPX2.5.0. And the energy and angular distribution of differential neutron yield by 2.5-MeV incident proton are also given in this part. In the following part, the character of epithermal neutron beam generated by 2.5-MeV incident protons is moderated by a new-designed moderator. Results: Energy spectra of neutrons generated by accelerator-based 7 Li(p, n) reaction with incident proton energy from 1.9 MeV to 3.0 MeV are got through the simulation and calculation. The best moderator thickness is got through comparison. Conclusions: Neutron beam produced by accelerator-based 7 Li(p, n) reaction, with the bombarding beam of 10 mA and the energy of 2.5 MeV, can meet the requirement of BNCT well after being moderated. (authors)

Boron isotope fractionation in column chromatography with glucamine type fibers

International Nuclear Information System (INIS)

Sonoda, Akinari; Makita, Yoji; Hirotsu, Takahiro

2008-01-01

Glucamine type polymers have specific affinity toward boric acid and borate ion. Among them, Chelest Fiber GRY-L showed larger fractionation for boron isotopes than other polymers in our previous study. For this study, we used Chelest Fibers with different fiber lengths (1.0 mm, 0.5 mm, and 0.3 mm) as column packing materials to perform chromatographic separation of boron isotopes. The shorter fiber has larger packing density when packed into the column using a dry method. The 0.3-mm-long fiber has a larger backpressure than fibers of other lengths. Boron adsorption capacities were measured using the breakthrough operation. At this time, the 0.5-mm-long fiber showed the highest capacity. When we measured the isotope ratio profile for fibers of different length using column chromatography, 0.5-mm-long fibers displayed the highest boron isotope fractionation. The 0.5-mm-long fiber is promising as a packing material of column chromatography for boron isotope separation. We also changed operation methods. The lower eluent concentration and the slower flow rate are suitable for boron isotope separation. (author)

Method for producing polycrystalline boron nitride

International Nuclear Information System (INIS)

Alexeevskii, V.P.; Bochko, A.V.; Dzhamarov, S.S.; Karpinos, D.M.; Karyuk, G.G.; Kolomiets, I.P.; Kurdyumov, A.V.; Pivovarov, M.S.; Frantsevich, I.N.; Yarosh, V.V.

1975-01-01

A mixture containing less than 50 percent of graphite-like boron nitride treated by a shock wave and highly defective wurtzite-like boron nitride obtained by a shock-wave method is compressed and heated at pressure and temperature values corresponding to the region of the phase diagram for boron nitride defined by the graphite-like compact modifications of boron nitride equilibrium line and the cubic wurtzite-like boron nitride equilibrium line. The resulting crystals of boron nitride exhibit a structure of wurtzite-like boron nitride or of both wurtzite-like and cubic boron nitride. The resulting material exhibits higher plasticity as compared with polycrystalline cubic boron nitride. Tools made of this compact polycrystalline material have a longer service life under impact loads in machining hardened steel and chilled iron. (U.S.)

A new target concept for proton accelerator driven boron neutron capture therapy applications

International Nuclear Information System (INIS)

Powell, J.R.; Ludewig, H.; Todosow, M.; Reich, M.

1998-01-01

A new target concept termed Discs Incorporating Sector Configured Orbiting Sources (DISCOS), is proposed for spallation applications, including BNCT (Boron Neutron Capture Therapy). In the BNCT application a proton beam impacts a sequence of ultra thin lithium DISCOS targets to generate neutrons by the 7 Li(p,n) 7 Be reaction. The proton beam loses only a few keV of its ∼MeV energy as it passes through a given target, and is re-accelerated to its initial energy, by a DC electric field between the targets

A simple and rapid method for measurement of 10B-para-boronophenylalanine in the blood for boron neutron capture therapy using fluorescence spectrophotometry

International Nuclear Information System (INIS)

Kashino, Genro; Fukutani, Satoshi; Suzuki, Minoru

2009-01-01

10 B deriving from 10 B-para-boronophenylalanine (BPA) and 10 B-borocaptate sodium (BSH) have been detected in blood samples of patients undergoing boron neutron capture therapy (BNCT) using prompt gamma ray spectrometer or Inductively Coupled Plasma (ICP) method, respectively. However, the concentration of each compound cannot be ascertained because boron atoms in both molecules are the target in these assays. Here, we propose a simple and rapid method to measure only BPA by detecting fluorescence based on the characteristics of phenylalanine. 10 B concentrations of blood samples from human or mice were estimated by the fluorescence intensities at 275 nm of a BPA excited by light of wavelength 257 nm using a fluorescence spectrophotometer. The relationship between fluorescence to increased BPA concentration showed a positive linear correlation. Moreover, we established an adequate condition for BPA measurement in blood samples containing BPA, and the estimated 10 B concentrations of blood samples derived from BPA treated mice were similar between the values obtained by our method and those by ICP method. This new assay will be useful to estimate BPA concentration in blood samples obtained from patients undergoing BNCT especially in a combination use of BSH and BPA. (author)

Thermal desorption spectroscopy of boron/carbon films after keV deuterium irradiation

International Nuclear Information System (INIS)

Yamaki, T.; Gotoh, Y.; Ando, T.; Jimbou, R.; Ogiwara, N.; Saidoh, M.

1994-01-01

Thermal desorption spectroscopy (TDS) of D 2 and CD 4 was done on boron/carbon films (B/(B+C)=0-74%), after 3 keV D 3 + irradiation to 4.5x10 17 D/cm 2 at 473 K. The D 2 desorption peaks were observed at 1050, 850 and 650 K. For a sputter B/C film (0%), only the 1050 K peak was observed. With increasing boron concentration to 3%, a sharp peak appeared at 850 K, the intensity of which was found to increase with increasing boron concentration to 23%, and then to decrease at 74%. The 650 K shoulder, which was observed for high boron concentration specimens, was speculated to be deuterium trapped by boron atoms in the boron clusters. The relative amount of CD 4 desorption was found to decrease with increasing boron concentration, which was attributed to the decrease in the trapped deuterium concentration in the implantation layer at temperatures at which CD 4 desorption proceeds. ((orig.))

Tribological properties of nitrogen implanted and boron implanted steels

International Nuclear Information System (INIS)

Kern, K.T.

1996-01-01

Samples of a steel with high chrome content was implanted separately with 75 keV nitrogen ions and with 75 keV boron ions. Implanted doses of each ion species were 2-, 4-, and 8 x 10 17 /cm 2 . Retained doses were measured using resonant non-Rutherford Backscattering Spectrometry. Tribological properties were determined using a pin-on-disk test with a 6-mm diameter ruby pin with a velocity of 0.94 m/min. Testing was done at 10% humidity with a load of 377 g. Wear rate and coefficient of friction were determined from these tests. While reduction in the wear rate for nitrogen implanted materials was observed, greater reduction (more than an order of magnitude) was observed for boron implanted materials. In addition, reduction in the coefficient of friction for high-dose boron implanted materials was observed. Nano-indentation revealed a hardened layer near the surface of the material. Results from grazing incidence x-ray diffraction suggest the formation of Fe 2 N and Fe 3 N in the nitrogen implanted materials and Fe 3 B in the boron implanted materials. Results from transmission electron microscopy will be presented

Boron-11 MRI and MRS of intact animals infused with a boron neutron capture agent

International Nuclear Information System (INIS)

Kabalka, G.W.; Davis, M.; Bendel, P.

1988-01-01

Boron neutron capture therapy (BNCT) depends on the delivery of boron-containing drugs to a targeted lesion. Currently, the verification and quantification of in vivo boron content is a difficult problem. Boron-11 spectroscopy was utilized to confirm the presence of a dimeric sulfhydryl dodecaborane BNCT agent contained in an intact animal. Spectroscopy experiments revealed that the decay time of transverse magnetization of the boron-11 spins was less than 1 ms which precluded the use of a 2DFT imaging protocol. A back-projection protocol was developed and utilized to generate the first boron-11 image of a BNCT agent in the liver of an intact Fisher 344 rat

Validation of dose planning calculations for boron neutron capture therapy using cylindrical and anthropomorphic phantoms

Energy Technology Data Exchange (ETDEWEB)

Koivunoro, Hanna; Seppaelae, Tiina; Uusi-Simola, Jouni; Merimaa, Katja; Savolainen, Sauli [Department of Physics, POB 64, FI-00014 University of Helsinki (Finland); Kotiluoto, Petri; Seren, Tom; Auterinen, Iiro [VTT Technical Research Centre of Finland, Espoo, POB 1000, FI-02044 VTT (Finland); Kortesniemi, Mika, E-mail: hanna.koivunoro@helsinki.f [HUS Helsinki Medical Imaging Center, University of Helsinki, POB 340, FI-00029 HUS (Finland)

2010-06-21

In this paper, the accuracy of dose planning calculations for boron neutron capture therapy (BNCT) of brain and head and neck cancer was studied at the FiR 1 epithermal neutron beam. A cylindrical water phantom and an anthropomorphic head phantom were applied with two beam aperture-to-surface distances (ASD). The calculations using the simulation environment for radiation application (SERA) treatment planning system were compared to neutron activation measurements with Au and Mn foils, photon dose measurements with an ionization chamber and the reference simulations with the MCNP5 code. Photon dose calculations using SERA differ from the ionization chamber measurements by 2-13% (disagreement increased along the depth in the phantom), but are in agreement with the MCNP5 calculations within 2%. The {sup 55}Mn(n,{gamma}) and {sup 197}Au(n,{gamma}) reaction rates calculated using SERA agree within 10% and 8%, respectively, with the measurements and within 5% with the MCNP5 calculations at depths >0.5 cm from the phantom surface. The {sup 55}Mn(n,{gamma}) reaction rate represents the nitrogen and boron depth dose within 1%. Discrepancy in the SERA fast neutron dose calculation (of up to 37%) is corrected if the biased fast neutron dose calculation option is not applied. Reduced voxel cell size ({<=}0.5 cm) improves the SERA calculation accuracy on the phantom surface. Despite the slight overestimation of the epithermal neutrons and underestimation of the thermal neutrons in the beam model, neutron calculation accuracy with the SERA system is sufficient for reliable BNCT treatment planning with the two studied treatment distances. The discrepancy between measured and calculated photon dose remains unsatisfactorily high for depths >6 cm from the phantom surface. Increasing discrepancy along the phantom depth is expected to be caused by the inaccurately determined effective point of the ionization chamber.

Polyamorphism and substructure of short-range order in amorphous boron films

International Nuclear Information System (INIS)

Palatnik, L.S.; Nechitajlo, A.A.; Koz'ma, A.A.

1981-01-01

The structure and substructure of boron amorphous films are studied in detail. Amorphous condensate of Bsup(a) boron is built of the same (but only disorientedly located) 12 B icosahedrons as boron crystalline modifications: B 105 -equilibrium β-rhombic, metastable: B 50 -tetragonal, B 12 -α-rhombohedral Coordination number for Bsup(a) (Z 1 =6.4) is lower than in B 105 (Z 1 =6.6) but higher than in B 50 modification (Z 1 =6.1). In crystalline modifications B 105 , B 50 , B 12 coordination numbers ω in first coordination spheres of icosahedrons are equal to ν 105 =6+4.6=10.6; ν 50 =10+3=14; ν 12 =6 respectively. Both amorphous modifications of boron Bsub(1)sup(a) and Bsub(15)sup(a) are analogs to B 50 in respect of the short-range order of icosahedron location. The difference between them is in ''substructure'' of short-range order: part of boron atoms (approximately 12%) do not occupy the vertices (so that vacancies appear) and enter the emptinesses between icosahedrons. In other words, the structure B 50 is the model basis of both amorphous phases [ru

β-Rhombohedral Boron: At the Crossroads of the Chemistry of Boron and the Physics of Frustration [Boron: a frustrated element

Energy Technology Data Exchange (ETDEWEB)

Ogitsu, Tadashi [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schwegler, Eric [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Galli, Giulia [Univ. of California, Davis, CA (United States)

2013-05-08

In the periodic table boron occupies a peculiar, crossover position: on the first row, it is surrounded by metal forming elements on the left and by non-metals on the right. In addition, it is the only non-metal of the third column. Therefore it is perhaps not surprising that the crystallographic structure and topology of its stable allotrope at room temperature (β-boron) are not shared by any other element, and are extremely complex. The formidable intricacy of β- boron, with interconnecting icosahedra, partially occupied sites, and an unusually large number of atoms per unit cell (more than 300) has been known for more than 40 years. Nevertheless boron remains the only element purified in significant quantities whose ground state geometry has not been completely determined by experiments. However theoretical progress reported in the last decade has shed light on numerous properties of elemental boron, leading to a thorough characterization of its structure at ambient conditions, as well as of its electronic and thermodynamic properties. This review discusses in detail the properties of β-boron, as inferred from experiments and the ab-initio theories developed in the last decade.

Proton magnetic resonance spectroscopy of a boron neutron capture therapy 10B-carrier, L-p-boronophenylalanine-fructose complex

Energy Technology Data Exchange (ETDEWEB)

Timonen, M.

2010-07-01

Boron neutron capture therapy (BNCT) is a radiotherapy that has mainly been used to treat malignant brain tumours, melanomas, and head and neck cancer. In BNCT, the patient receives an intravenous infusion of a 10B-carrier, which accumulates in the tumour area. The tumour is irradiated with epithermal or thermal neutrons, which result in a boron neutron capture reaction that generates heavy particles to damage tumour cells. In Finland, boronophenylalanine fructose (BPA-F) is used as the 10B-carrier. Currently, the drifting of boron from blood to tumour as well as the spatial and temporal accumulation of boron in the brain, are not precisely known. Proton magnetic resonance spectroscopy (1H MRS) could be used for selective BPA-F detection and quantification as aromatic protons of BPA resonate in the spectrum region, which is clear of brain metabolite signals. This study, which included both phantom and in vivo studies, examined the validity of 1H MRS as a tool for BPA detection. In the phantom study, BPA quantification was studied at 1.5 and 3.0 T with single voxel 1H MRS, and at 1.5 T with magnetic resonance imaging (MRSI). The detection limit of BPA was determined in phantom conditions at 1.5 T and 3.0 T using single voxel 1H MRS, and at 1.5 T using MRSI. In phantom conditions, BPA quantification accuracy of +- 5% and +- 15% were achieved with single voxel MRS using external or internal (internal water signal) concentration references, respectively. For MRSI, a quantification accuracy of <5% was obtained using an internal concentration reference (creatine). The detection limits of BPA in phantom conditions for the PRESS sequence were 0.7 (3.0 T) and 1.4 mM (1.5 T) mM with 20 x 20 single voxel MRS, and 1.0 mM with acquisition-weighted MRSI, respectively. In the in vivo study, an MRSI or single voxel MRS or both was performed for ten patients (patients 1-10) on the day of BNCT. Three patients had glioblastoma multiforme (GBM), and five patients had a recurrent or

Response of soybean plants to phosphorus, boron and molybdenum fertilization

International Nuclear Information System (INIS)

Abdel-Aziz, H. A.; Aly, M. E.

2012-12-01

A pot experiment was carried out to study the effect of added phosphorus levels (30. 60 kg p/fed) with the addition of boron at (2, 6 ppm) and molybdenum at (5, 10.ppm) and without addition beside the control the control on growth and mineral content and root nodules in soybean plants. The results indicated that the effect of phosphorus on the formation of nodules had a clear effect when added with boron, molybdenum and when boron added at a rate of 2 ppm in the absence of phosphorus led to increase in root nodules in each of the 5, 10 ppm led to increased formation of, naldetuss in of the alluvial and calcareous soil. The molybdenum, nitrogen and phosphorus uptake increased directly proportional to the result of increased rate of addition of phosphorus and molybdenum. While the uptake born may be added with the rate of increased concentration of 2 ppm, while when added at 6 ppm led tp increased absorption of boron in the calcareous soil, but led to a decrease in the alluvial soils. (Author)

A method of beam control for NFZ-10 industrial irradiation linac

International Nuclear Information System (INIS)

Zhao Minghua

2000-01-01

Traditionally negative feedback coming from output beam is used to stabilize output beam by regulating filament voltage of bombarding diode electron gun. The authors analysed the shortcomings of the method in detail and put forward a new method of regulating bombarding high voltage in NFZ-10 industrial irradiation linac. Output beam with high stability and high accuracy was obtained

Understanding Boron through Size-Selected Clusters: Structure, Chemical Bonding, and Fluxionality

Energy Technology Data Exchange (ETDEWEB)

Sergeeva, Alina P.; Popov, Ivan A.; Piazza, Zachary A.; Li, Wei-Li; Romanescu, Constantin; Wang, Lai S.; Boldyrev, Alexander I.

2014-04-15

Conspectus Boron is an interesting element with unusual polymorphism. While three-dimensional (3D) structural motifs are prevalent in bulk boron, atomic boron clusters are found to have planar or quasi-planar structures, stabilized by localized two-center–two-electron (2c–2e) σ bonds on the periphery and delocalized multicenter–two-electron (nc–2e) bonds in both σ and π frameworks. Electron delocalization is a result of boron’s electron deficiency and leads to fluxional behavior, which has been observed in B13+ and B19–. A unique capability of the in-plane rotation of the inner atoms against the periphery of the cluster in a chosen direction by employing circularly polarized infrared radiation has been suggested. Such fluxional behaviors in boron clusters are interesting and have been proposed as molecular Wankel motors. The concepts of aromaticity and antiaromaticity have been extended beyond organic chemistry to planar boron clusters. The validity of these concepts in understanding the electronic structures of boron clusters is evident in the striking similarities of the π-systems of planar boron clusters to those of polycyclic aromatic hydrocarbons, such as benzene, naphthalene, coronene, anthracene, or phenanthrene. Chemical bonding models developed for boron clusters not only allowed the rationalization of the stability of boron clusters but also lead to the design of novel metal-centered boron wheels with a record-setting planar coordination number of 10. The unprecedented highly coordinated borometallic molecular wheels provide insights into the interactions between transition metals and boron and expand the frontier of boron chemistry. Another interesting feature discovered through cluster studies is boron transmutation. Even though it is well-known that B–, formed by adding one electron to boron, is isoelectronic to carbon, cluster studies have considerably expanded the possibilities of new structures and new materials using the B�

Current status of boron neutron capture therapy of high grade gliomas and recurrent head and neck cancer

Directory of Open Access Journals (Sweden)

Barth Rolf F

2012-08-01

Full Text Available Abstract Boron neutron capture therapy (BNCT is a biochemically targeted radiotherapy based on the nuclear capture and fission reactions that occur when non-radioactive boron-10, which is a constituent of natural elemental boron, is irradiated with low energy thermal neutrons to yield high linear energy transfer alpha particles and recoiling lithium-7 nuclei. Clinical interest in BNCT has focused primarily on the treatment of high grade gliomas, recurrent cancers of the head and neck region and either primary or metastatic melanoma. Neutron sources for BNCT currently have been limited to specially modified nuclear reactors, which are or until the recent Japanese natural disaster, were available in Japan, United States, Finland and several other European countries, Argentina and Taiwan. Accelerators producing epithermal neutron beams also could be used for BNCT and these are being developed in several countries. It is anticipated that the first Japanese accelerator will be available for therapeutic use in 2013. The major hurdle for the design and synthesis of boron delivery agents has been the requirement for selective tumor targeting to achieve boron concentrations in the range of 20 μg/g. This would be sufficient to deliver therapeutic doses of radiation with minimal normal tissue toxicity. Two boron drugs have been used clinically, a dihydroxyboryl derivative of phenylalanine, referred to as boronophenylalanine or “BPA”, and sodium borocaptate or “BSH” (Na2B12H11SH. In this report we will provide an overview of other boron delivery agents that currently are under evaluation, neutron sources in use or under development for BNCT, clinical dosimetry, treatment planning, and finally a summary of previous and on-going clinical studies for high grade gliomas and recurrent tumors of the head and neck region. Promising results have been obtained with both groups of patients but these outcomes must be more rigorously evaluated in larger

Application of drug delivery system for boron neutron capture therapy. Basic research toward clinical application

International Nuclear Information System (INIS)

Yanagie, Hironobu; Takahashi, Hiroyuki

2010-01-01

Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between 10 B and thermal neutrons ( 10 B+ 1 n → 7 Li+ 4 He (α) +2.31 MeV (93.7%)/2.79 MeV (6.3%)). The resulting lithium ions and αparticles are high linear energy transfer (LET) particles which give high biological effect. Their short range in tissue (5-9 μm) restricts radiation damage to those cells in which boron atoms are located at the time of neutron irradiation. BNCT has been applied clinically for the treatment of malignant brain tumors, malignant melanoma, head and neck cancer and hepatoma etc, recently. Sodium borocaptate (Na 2 10 B 12 H 11 SH; BSH) and borono-phenylalanine ( 10 BPA) are currently being used in clinical treatments. To achieve the selective delivery of boron atoms to cancer cells, drug delivery system (DDS) becomes an attractive intelligent technology as targeting and controlled release of drugs. We have firstly reported that 10 B atoms delivered by immunoliposomes are cytotoxic to human pancreatic carcinoma cells (AsPC-1) after thermal neutron irradiation in vitro. The intra-tumoural injection of boronated immunoliposomes can increase the retention of 10 B atoms in tumour cells, causing suppression of tumour growth in vivo following thermal neutron irradiation. We prepared polyethylene-glycol binding liposomes (PEG-liposomes) as an effective 10 B carrier to obviate phagocytosis by reticuloendotherial systems. We had prepared 10 BSH entrapped Water-in-Oil-in-Water (WOW) emulsion. The 10 B concentration in VX-2 tumour after intra-arterial injection of 10 BSH entrapped WOW emulsion was superior to the groups of 10 BSH entrapped conventional Lipiodol mix emulsion. 10 Boron entrapped WOW emulsion is one of the most useful for intra-arterial boron delivery carrier on BNCT to hepatocellular carcinoma. (author)

Epithermal neutron activation analysis using a boron carbide irradiation filter

International Nuclear Information System (INIS)

Ehmann, W.D.; Brueckner, J.

1980-01-01

The use of boron carbide as a thermal neutron filter in epithermal neutron activation (ENAA) analysis has been investigated. As compared to the use of a cadmium filter, boron provides a greater reduction of activities from elements relatively abundant in terrestrial rocks and fossil fuels, such as Na, La, Sc and Fe. These elements have excitation functions which follow the 1/v law in the 1 to 10 eV lower epithermal region. This enhances the sensitivity of ENAA for elements such as U, Th, Ba and etc. which have strong resonances in the higher epithermal region above 10 eV. In addition, a boron carbide filter has the advantages over cadmium of acquiring a relatively low level of induced activity which poses minimal radiation safety problems, when used for ENAA. (author)

Functional characterization of Citrus macrophylla BOR1 as a boron transporter.

Science.gov (United States)

Cañon, Paola; Aquea, Felipe; Rodríguez-Hoces de la Guardia, Amparo; Arce-Johnson, Patricio

2013-11-01

Plants have evolved to develop an efficient system of boron uptake and transport using a range of efflux carriers named BOR proteins. In this work we isolated and characterized a boron transporter of citrus (Citrus macrophylla), which was named CmBOR1 for its high homology to AtBOR1. CmBOR1 has 4403 bp and 12 exons. Its coding region has 2145 bp and encodes for a protein of 714 amino acids. CmBOR1 possesses the molecular features of BORs such as an anion exchanger domain and the presence of 10 transmembrane domains. Functional analysis in yeast indicated that CmBOR1 has an efflux boron transporter activity, and transformants have increased tolerance to excess boron. CmBOR1 is expressed in leaves, stem and flowers and shows the greatest accumulation in roots. The transcript accumulation was significantly increased under boron deficiency conditions in shoots. In contrast, the accumulation of the transcript did not change in boron toxicity conditions. Finally, we observed that constitutive expression of CmBOR1 was able to increase tolerance to boron deficiency conditions in Arabidopsis thaliana, suggesting that CmBOR1 is a xylem loading boron transporter. Based on these results, it was determined that CmBOR1 encodes a boric acid/borate transporter involved in tolerance to boron deficiency in plants. © 2013 Scandinavian Plant Physiology Society.

Considerations for boron neutron capture therapy studies; Consideracoes sobre o estudo da BNCT (terapia de captura neutronica por boro)

Energy Technology Data Exchange (ETDEWEB)

Faria Gaspar, P de

1994-12-31

Radiotherapy is indispensable as a mean to eradicate deeply or infiltrating tumor tissue that can not be removed surgically. Therefore, it is not selective and may also kill the surrounding health tissue. The principle of BNCT (Boron Neutron Capture Therapy) consist in targeting a tumor selectively with a boron-10 compound. This nuclide has a large capture cross section for thermal neutrons and the nuclear reaction and the delivered energy in locus will selective the tumor. Since its initial proposal in 1963 BNCT has made much progress, however it is not used in a routine treatment. In this work it was approached some complex procedures, as the obtention of selective boron compounds, the adequate set up of neutron beams, the biodistribution, the in vivo and in vitro studies, and also human patients treatments. This work provide fundamentals about BNCT to professional of different areas of knowledge since it comprises multidisciplinary study. It includes appendixes for the ones not related to the field for a better comprehension of the many aspects involved. It is also presented a glossary containing technical and basic aspects involved. It is also presented a glossary containing technical and basic terms referred in the work. (author). 174 refs, 1 fig, 12 apps.

10 September: the LHC’s first circulating beam

CERN Multimedia

On 10 September, a first beam of protons will circulate in the LHC. The first moments in the life of the LHC will be an exciting time for the CERN staff, and will be captured by more than 250 media organizations from all over the world. The first injection of the beam into the machine will be between 9:00 and 10:00 a. m. At 9:15 the LHC project leader, Lyn Evans, will give a brief explanation of the day’s proceedings in French followed by some words from Robert Aymar, CERN Director general. CERN personnel are invited to follow the first beam day events, which will be shown in the following rooms around CERN: All day: Council Chamber, Main Auditorium, IT Auditorium, AB Auditorium Prévessin, Conference Room 40-S2-A01, Conference Room 40-S2-C01. Afternoon: AB Auditorium Meyrin, AT Auditorium. Please note that the event will also be webcast but, given the limited number of connections, this option is intended for use of the public outside CERN. CERN personnel are encouraged to follow the event from the confe...

Hydrolytic Stability of Boronate Ester-Linked Covalent Organic Frameworks

KAUST Repository

Li, Huifang

2018-01-30

The stability of covalent organic frameworks (COFs) is essential to their applications. However, the common boronate ester-linked COFs are susceptible to attack by nucleophiles (such as water molecules) at the electron-deficient boron sites. To provide an understanding of the hydrolytic stability of the representative boronate ester-linked COF-5 and of the associated hydrolysis mechanisms, density functional theory (DFT) calculations were performed to characterize the hydrolysis reactions of the molecule formed by the condensation of 1,4-phenylenebis(boronic acid) (PBBA) and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) monomers; two cases were considered, one dealing with the freestanding molecule and the other with the molecule interacting with COF layers. It was found that the boronate ester (B–O) bond dissociation, which requires one H2O molecule, has a relatively high energy barrier of 22.3 kcal mol−1. However, the presence of an additional H2O molecule significantly accelerates hydrolysis by reducing the energy barrier by a factor of 3. Importantly, the hydrolysis of boronate ester bonds situated in a COF environment follows reaction pathways that are different and have increased energy barriers. These results point to an enhanced hydrolytic stability of COF-5 crystals.

Synthesis and crystal structure of Mg2B24C, a new boron-rich boride related to 'tetragonal boron I'

International Nuclear Information System (INIS)

Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

2006-01-01

Single crystals of Mg 2 B 24 C, a new boron-rich boridecarbide of magnesium, were synthesized as black needles and columns by reaction of the elements in Ta ampoules and BN crucibles at 1300 deg. C. The crystal structure was determined by X-ray diffraction (P-4n2, a=8.9391(13)A, c=5.0745(10)A, Z=2, 713 reflections, 64 variables, R 1 (F)=0.0235, wR 2 (I)=0.0591). It is closely related to 'tetragonal boron I' and can be described as a tetragonal rod packing of corner-linked B 12 icosahedra with C and Mg atoms in the voids. Each B 12 icosahedron has 2 B-C bonds and 10 exohedral bonds to other icosahedra, 2 within the rod and 4x2 to neighbouring rods. The isolated C atoms are 4-fold coordinated forming distorted tetrahedra. Mg is placed on two crystallographically independent positions within the three-dimensional B 12 C network. Mg 2 B 24 C is the first example for a compound related to 'tetragonal boron I' with a stoichiometric composition

Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride–hydroxy apatite in rat femurs

Energy Technology Data Exchange (ETDEWEB)

Atila, Alptug, E-mail: alptugatila@yahoo.com [Department of Analytical Chemistry, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Halici, Zekai; Cadirci, Elif [Department of Pharmacology, Faculty of Medicine, Ataturk University, Erzurum 25240 (Turkey); Karakus, Emre [Department of Pharmacology and Toxicology, School of Veterinary Medicine, Ataturk University, Erzurum 25240 (Turkey); Palabiyik, Saziye Sezin [Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Ay, Nuran [Department of Material Science and Engineering, Faculty of Engineering, Anadolu University, Eskisehir 26555 (Turkey); Bakan, Feray [Sabancı University Nanotechnology Research and Application Center (SUNUM), Istanbul 34956 (Turkey); Yilmaz, Sahin [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul 34755 (Turkey)

2016-01-01

ABSTRACT: Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN–HA composites in rat femurs. All rats were (n = 126) divided into five experimental groups (n = 24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100HA (Group2), femoral defect + %2.5hBN + %97.5HA (Group3), femoral defect + %5hBN + %95HA (Group4), femoral defect + %10hBN + %90 HA (Group5), femoral defect + %100hBN (Group6). The femoral defect was created in the distal femur (3 mm drill-bit). Each implant group was divided into four different groups (n = 24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN–HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN–HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. - Highlights: • Nano-hBN–HA composites are new targets for biomaterial and implant bioengineers. • Serum boron levels were researched after implantation of nano-hBN–HA composites. • Implantation of hBN–HA composite did not result in increased serum boron levels. • The use of boron in composite form with HA did not change the stability of the implant.

Nanopores creation in boron and nitrogen doped polycrystalline graphene: A molecular dynamics study

Science.gov (United States)

Izadifar, Mohammadreza; Abadi, Rouzbeh; Nezhad Shirazi, Ali Hossein; Alajlan, Naif; Rabczuk, Timon

2018-05-01

In the present paper, molecular dynamic simulations have been conducted to investigate the nanopores creation on 10% of boron and nitrogen doped polycrystalline graphene by silicon and diamond nanoclusters. Two types of nanoclusters based on silicon and diamond are used to investigate their effect for the fabrication of nanopores. Therefore, three different diameter sizes of the clusters with five kinetic energies of 10, 50, 100, 300 and 500 eV/atom at four different locations in boron or nitrogen doped polycrystalline graphene nanosheets have been perused. We also study the effect of 3% and 6% of boron doped polycrystalline graphene with the best outcome from 10% of doping. Our results reveal that the diamond cluster with diameter of 2 and 2.5 nm fabricates the largest nanopore areas on boron and nitrogen doped polycrystalline graphene, respectively. Furthermore, the kinetic energies of 10 and 50 eV/atom can not fabricate nanopores in some cases for silicon and diamond clusters on boron doped polycrystalline graphene nanosheets. On the other hand, silicon and diamond clusters fabricate nanopores for all locations and all tested energies on nitrogen doped polycrystalline graphene. The area sizes of nanopores fabricated by silicon and diamond clusters with diameter of 2 and 2.5 nm are close to the actual area size of the related clusters for the kinetic energy of 300 eV/atom in all locations on boron doped polycrystalline graphene. The maximum area and the average maximum area of nanopores are fabricated by the kinetic energy of 500 eV/atom inside the grain boundary at the center of the nanosheet and in the corner of nanosheet with diameters of 2 and 3 nm for silicon and diamond clusters on boron and nitrogen doped polycrystalline graphene.

Ion implantation of boron in germanium

International Nuclear Information System (INIS)

Jones, K.S.

1985-05-01

Ion implantation of 11 B + into room temperature Ge samples leads to a p-type layer prior to any post implant annealing steps. Variable temperature Hall measurements and deep level transient spectroscopy experiments indicate that room temperature implantation of 11 B + into Ge results in 100% of the boron ions being electrically active as shallow acceptor, over the entire dose range (5 x 10 11 /cm 2 to 1 x 10 14 /cm 2 ) and energy range (25 keV to 100 keV) investigated, without any post implant annealing. The concentration of damage related acceptor centers is only 10% of the boron related, shallow acceptor center concentration for low energy implants (25 keV), but becomes dominant at high energies (100 keV) and low doses ( 12 /cm 2 ). Three damage related hole traps are produced by ion implantation of 11 B + . Two of these hole traps have also been observed in γ-irradiated Ge and may be oxygen-vacancy related defects, while the third trap may be divacancy related. All three traps anneal out at low temperatures ( 0 C). Boron, from room temperature implantation of BF 2 + into Ge, is not substitutionally active prior to a post implant annealing step of 250 0 C for 30 minutes. After annealing additional shallow acceptors are observed in BF 2 + implanted samples which may be due to fluorine or flourine related complexes which are electrically active

Boron effects on creep rupture strength of W containing advanced ferritic creep resistant steels

Energy Technology Data Exchange (ETDEWEB)

Mito, N.; Hasegawa, Y. [Tohoku Univ., Sendai (Japan)

2010-07-01

The creep strength in ferritic creep resistant steels is increased by boron addition. However, the strengthening mechanisms have not yet been studied. This study clarifies the strengthening mechanism of 9% chromium steels with 10{proportional_to}100ppm boron and 0.5{proportional_to}2.0mass% tungsten in the laboratory. The strengthening effect of simultaneous addition of boron and tungsten was analyzed by hardenability, room-temperature strength and creep tests at 650 C. Changes in the microstructure as a result of the addition of boron and tungsten were also examined by optical microscope and transmission electron microscope (TEM). In addition, Alpha-ray Track Etching (ATE) method was used to detect the boron distribution and analyze the mechanisms change in the mechanical properties. Boron addition did not affect room-temperature strength, however, simultaneous addition of boron and tungsten increased room-temperature and high-temperature strength. According to ATE analysis, boron exists at the grain boundary. Therefore, synergistic effects of boron and tungsten on the creep strength suggest the tungsten precipitates stabilization by boron at the grain boundary. (orig.)

Experimental Studies of Boronophenylalanine ({sup 10}BPA) Biodistribution for the Individual Application of Boron Neutron Capture Therapy (BNCT) for Malignant Melanoma Treatment

Energy Technology Data Exchange (ETDEWEB)

Carpano, Marina; Perona, Marina; Rodriguez, Carla [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); Nievas, Susana; Olivera, Maria; Santa Cruz, Gustavo A. [Department of Boron Neutron Capture Therapy, National Atomic Energy Commission, San Martín (Argentina); Brandizzi, Daniel; Cabrini, Romulo [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); School of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Pisarev, Mario [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina); Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires (Argentina); Juvenal, Guillermo Juan [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina); Dagrosa, Maria Alejandra, E-mail: dagrosa@cnea.gov.ar [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina)

2015-10-01

Purpose: Patients with the same histopathologic diagnosis of cutaneous melanoma treated with identical protocols of boron neutron capture therapy (BNCT) have shown different clinical outcomes. The objective of the present studies was to evaluate the biodistribution of boronophenilalanina ({sup 10}BPA) for the potential application of BNCT for the treatment of melanoma on an individual basis. Methods and Materials: The boronophenilalanine (BPA) uptake was evaluated in 3 human melanoma cell lines: MEL-J, A375, and M8. NIH nude mice were implanted with 4 10{sup 6} MEL-J cells, and biodistribution studies of BPA (350 mg/kg intraperitoneally) were performed. Static infrared imaging using a specially modified infrared camera adapted to measure the body infrared radiance of small animals was used. Proliferation marker, Ki-67, and endothelial marker, CD31, were analyzed in tumor samples. Results: The in vitro studies demonstrated different patterns of BPA uptake for each analyzed cell line (P<.001 for MEL-J and A375 vs M8 cells). The in vivo studies showed a maximum average boron concentration of 25.9 ± 2.6 μg/g in tumor, with individual values ranging between 11.7 and 52.0 μg/g of {sup 10}B 2 hours after the injection of BPA. Tumor temperature always decreased as the tumors increased in size, with values ranging between 37°C and 23°C. A significant correlation between tumor temperature and tumor-to-blood boron concentration ratio was found (R{sup 2} = 0.7, rational function fit). The immunohistochemical studies revealed, in tumors with extensive areas of viability, a high number of positive cells for Ki-67, blood vessels of large diameter evidenced by the marker CD31, and a direct logistic correlation between proliferative status and boron concentration difference between tumor and blood (R{sup 2} = 0.81, logistic function fit). Conclusion: We propose that these methods could be suitable for designing new screening protocols applied before melanoma BNCT

Study on the preparation of boron-rich film by magnetron sputtering in oxygen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Pan, Zhangmin; Yang, Yiming; Huang, Jian; Ren, Bing; Yu, Hongze; Xu, Run; Ji, Huanhuan; Wang, Lin; Wang, Linjun, E-mail: ljwang@shu.edu.cn

2016-12-01

Highlights: • Boron ({sup 10}B) oxide films were successfully grown using RF magnetron sputtering. • Effects of oxygen partial pressure on the property of the films were studied. • Substrates were covered with B-rich film and film surface was covered with B{sub 2}O{sub 3}. • The growth mechanism of films in oxygen atmosphere was analyzed using XPS. - Abstract: In this paper, the growth of boron ({sup 10}B) oxide films on (1 0 0) silicon substrate were achieved by radio frequency (r.f.) magnetron sputtering under the different oxygen partial pressure with a target of boron and boron oxide. The structure and properties of deposited films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The results showed that the substrate was covered with boron-rich films tightly and the surface of films was covered with B{sub 2}O{sub 3}. And the growth mechanism of boron-rich film in oxygen atmosphere was also analyzed.

Friction and wear performance of diamond-like carbon, boron carbide, and titanium carbide coatings against glass

International Nuclear Information System (INIS)

Daniels, B.K.; Brown, D.W.; Kimock, F.M.

1997-01-01

Protection of glass substrates by direct ion beam deposited diamond-like carbon (DLC) coatings was observed using a commercial pin-on-disk instrument at ambient conditions without lubrication. Ion beam sputter-deposited titanium carbide and boron carbide coatings reduced sliding friction, and provided tribological protection of silicon substrates, but the improvement factor was less than that found for DLC. Observations of unlubricated sliding of hemispherical glass pins at ambient conditions on uncoated glass and silicon substrates, and ion beam deposited coatings showed decreased wear in the order: uncoated glass>uncoated silicon>boron carbide>titanium carbide>DLC>uncoated sapphire. Failure mechanisms varied widely and are discussed. Generally, the amount of wear decreased as the sliding friction decreased, with the exception of uncoated sapphire substrates, for which the wear was low despite very high friction. There is clear evidence that DLC coatings continue to protect the underlying substrate long after the damage first penetrates through the coating. The test results correlate with field use data on commercial products which have shown that the DLC coatings provide substantial extension of the useful lifetime of glass and other substrates. copyright 1997 Materials Research Society

Boronated liposome development and evaluation

International Nuclear Information System (INIS)

Hawthorne, M.F.

1995-01-01

The boronated liposome development and evaluation effort consists of two separate tasks. The first is the development of new boron compounds and the synthesis of known boron species with BNCT potential. These compounds are then encapsulated within liposomes for the second task, biodistribution testing in tumor-bearing mice, which examines the potential for the liposomes and their contents to concentrate boron in cancerous tissues

Studies related to antibody-mediated boron delivery for BNCT

International Nuclear Information System (INIS)

Hawthorne, M.F.; Varadarajan, A.; Paxton, R.J.; Beatty, B.G.; Curtis, F.L.

1992-01-01

Of the many methods of selective boron delivery to tumor presently under consideration the use of boron-labeled tumor-targeted monoclonal antibodies (Mabs) and their immunoreactive fragments appears to offer the most general, but complex, approach. Assuming that tumor cells generally carry 10 6 characteristic antigenic sites of any one type and that there are approximately 10 9 cells per gram of tumor, one calculates that about 600 10 B atoms must be attached to each individual Mab molecule (if all antigenic sites are complexed) for each 10 ppm of 10 B supplied to tumor. Rather than randomly attack IgG Mab molecules with a large number of relatively small boron-containing conjugation reagent molecules the authors have chosen to assemble a series of discrete, precisely synthesized oligomeric reagents ('trailers') each of which contains a fixed number of B-atoms up to approximately 200. These oligomeric reagents would carry a radioactive or fluorescent group for analytical purposes attached to a terminal-NH 2 group of their chain and the remaining -COOH terminus would be free for conjugation with the lysine var-epsilon-NH 2 groups of Mab protein. Two types of oligomeric trailer reagents are envisioned; hydrophilic peptides and polyamides

Influence of soil solution cation composition on boron adsorption by soils

Science.gov (United States)

Boron (B) adsorption on five arid-zone soil samples from California was investigated as a function of solution pH (4-10) and cation composition (Na, Ca, or Mg). Boron adsorption increased with increasing solution pH, reached an adsorption maximum near pH 9, and decreased with further increases with...

Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems.

Science.gov (United States)

Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen

2016-11-01

Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent. Copyright © 2016 Elsevier B.V. All rights reserved.

The Swedish facility for boron neutron capture therapy

Energy Technology Data Exchange (ETDEWEB)

Skoeld, K.; Capala, J. [Studsvik Medical AB (Sweden); Kierkegaard, J.; Haakansson, R. [Studsvik Nuclear AB (Sweden); Gudowska, I. [Karolinska Institute (Sweden)

2000-10-01

A BNCT (Boron Neutron Capture Therapy) facility has been constructed at the R2-0 reactor at Studsvik, Sweden. R2-0 is a 1 MW, open core, pool reactor. The reactor core is suspended on a movable tower and can be positioned anywhere in the pool. The BNCT facility includes two adjacent, parallel filter/moderator configurations and the reactor core is positioned in front of any of them as appropriate. One of the resulting neutron beams has been optimized for clinical irradiations with a filter/moderator system that allows easy variation of the neutron spectrum from the thermal to the epithermal energy range and with an extended collimator for convenient patient positioning. The other beam has been designed for radiobiological research and is equipped with a heavy water moderator and a large irradiation cavity with a uniform field of thermal neutrons. (author)

The Swedish facility for boron neutron capture therapy

International Nuclear Information System (INIS)

Skoeld, K.; Capala, J.; Kierkegaard, J.; Haakansson, R.; Gudowska, I.

2000-01-01

A BNCT (Boron Neutron Capture Therapy) facility has been constructed at the R2-0 reactor at Studsvik, Sweden. R2-0 is a 1 MW, open core, pool reactor. The reactor core is suspended on a movable tower and can be positioned anywhere in the pool. The BNCT facility includes two adjacent, parallel filter/moderator configurations and the reactor core is positioned in front of any of them as appropriate. One of the resulting neutron beams has been optimized for clinical irradiations with a filter/moderator system that allows easy variation of the neutron spectrum from the thermal to the epithermal energy range and with an extended collimator for convenient patient positioning. The other beam has been designed for radiobiological research and is equipped with a heavy water moderator and a large irradiation cavity with a uniform field of thermal neutrons. (author)

Synthesis and evaluation of boronated folates for BNCT

International Nuclear Information System (INIS)

Shukla, S.; Sekido, M.; Guo, W.; Mueller, R.; Sudimack, J.; Lee, R.J.; Tjarks, W.; Adams, D.M.; Barth, R.F.

2000-01-01

To study the possible utilization of folic acid as the 10 B carrier for BNCT, folic acid conjugated boron containing liposomes and starburst dendrimers were prepared. In both systems folic acid was used as the recognition part and polyethylene glycol (PEG) as the spacer. In vitro studies were carried out using folate receptor overexpressing 24JK-FBP and KB cells. The results indicated that these boronated folic acid conjugates were incorporated into the tumor cells via receptor-mediated endocytosis. (author)

Application of HVJ envelope system to boron neutron capture therapy (BNCT)

International Nuclear Information System (INIS)

Nakai, Kei; Kurooka, Masaaki; Kaneda, Yasufumi; Yamamoto, Tetsuya; Matsumura, Akira; Asano, Tomoyuki

2006-01-01

Boron Neutron Capture Therapy (BNCT) has been used clinically for the treatment of malignant tumors. Two drugs, p-boronophenylalanine (BPA) and sulfhydral borane (BSH), have been used as boron delivery agents. These drugs seem to be taken up preferentially in solid tumors, but it is uncertain whether therapeutic quantities of boron atoms are taken up by micro-invasive or distant tumor cells. High accumulation and high selective delivery of boron into tumor tissues are the most important requirements to achieve efficient BNCT for malignant tumor. The HVJ envelope (HVJ-E) vector system is a novel fusion-mediated gene delivery system based on inactivated hemagglutinating virus of Japan (HVJ; Sendai virus). Although we developed this vector system for gene transfer, it can also deliver proteins, synthetic oligonucleotides, and drugs. HVJ-liposome, which is liposome fused with HVJ-E, has higher boron trapping efficiency than HVJ-E alone. We report the boron delivery into cultured cells with HVJ-liposome systems. The cellular 10 B concentration after 60 min incubation with HVJ-E containing BSH was 24.9 μg/g cell pellet for BHK-21 cells (baby hamster kidney cells) and 19.4 μg/g cell pellet for SCC VII cells (murine squamous cell carcinoma). These concentrations are higher than that of 60 min incubated cells with BSH containing (100μg 10 B/ml) medium. These results indicate the HVJ-E fused with tumor cell membrane and rapidly delivered boron agents, and that the HVJ-E-mediated delivery system could be applicable to BNCT. Plans are underway to begin neutron radiation experiments in vivo and in vitro. (author)

Biodistribution, toxicity and efficacy of a boronated porphyrin for boron neutron capture therapy

International Nuclear Information System (INIS)

Miura, Michiko; Micca, P.; Fairchild, R.; Slatkin, D.; Gabel, D.

1992-01-01

Boron-containing porphyrins may be useful for boron neutron capture therapy (BNCT) in the treatment of brain tumors. Porphyrins have been shown to accumulate in tumor tissue and to be essentially excluded from normal brain. However, problems of toxicity may prevent some boron-containing porphyrins from being considered for BNCT. The authors have synthesized the boronated porphyrin 2,4-bis-vinyl-o-nidocarboranyl-deuteroporphyrin IX (VCDP). Preliminary studies in tumor-bearing mice showed considerable uptake of boron at a total dose of 150 μg/gbw with low mortality. They now report that a total dose to mice of ∼ 275 μg VCDP/gbw administered in multiple intraperitoneal (ip) injections can provide 40-50μg B per gram of tumor with acceptable toxicity. Toxicity experiments and a preliminary trial of BNCT in mice given such doses are also reported

Effect of boron implantation on the electrical and photoelectrical properties of e-beam deposited Ag-In-Se thin films

International Nuclear Information System (INIS)

Colakoglu, T; Parlak, M; Kulakci, M; Turan, R

2008-01-01

In this study, e-beam evaporated Ag-In-Se (AIS) thin films were doped by the implantation of boron (B) ions at 75 keV with a dose of 1 x 10 15 ions cm -2 and a subsequent annealing process was applied to the doped AIS films at different temperatures under nitrogen atmosphere. The effects of implantation and annealing on the electrical and photoelectrical properties of AIS thin films were investigated through temperature dependent conductivity, spectral photoresponse and photoconductivity measurements under different illumination intensities. The electrical conductivity measurements showed that the room temperature conductivity values were determined as 2.4 x 10 -7 (Ω cm) -1 , 1.7 x 10 -6 (Ω cm) -1 and 8.9 x 10 -5 (Ω cm) -1 for B-doped films (B0), B-doped and annealed films at 200 deg. C (B2) and at 300 deg. C (B3), respectively. It was observed that the electrical conductivity improved as the annealing temperature increased up to 400 deg. C at which the AIS thin films showed degenerate semiconductor behaviour. The spectral distribution of the photoresponse curves indicated three local maxima located at 1.63, 1.79 and 2.01 eV for B0 type films, 1.65, 1.87 and 2.07 eV for B2 type films and 1.73, 2.02 and 2.32 eV for B3 type films at room temperature. These three different energy values were ascribed to the splitting of the valence band due to spin-orbit interaction and crystalline lattice field effects. The first energy values of each set were determined to be energy band gaps of the AIS thin films. The photoconductivity measurements as a function of temperature and illumination intensity were performed on the B-doped AIS thin films in order to determine the nature of recombination processes in the films. The photoconductivity values were found to be thermally quenched for all types of thin films and the variation of photocurrent as a function of illumination intensity showed that the dependence of photocurrent on the intensity was supralinear. The two

High strain amount in recessed junctions induced by selectively deposited boron-doped SiGe layers

International Nuclear Information System (INIS)

Radamson, H.H.; Kolahdouz, M.; Ghandi, R.; Ostling, M.

2008-01-01

This work presents the selective epitaxial growth (SEG) of Si 1-x Ge x (x = 0.15-0.315) layers with high amount of boron (1 x 10 20 -1 x 10 21 cm -3 ) in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. The influence of the growth rate and strain on boron incorporation has been studied. A focus has been made on the strain distribution and boron incorporation in SEG of SiGe layers

Two-channel neutron boron meter

International Nuclear Information System (INIS)

Chen Yongqing; Yin Guowei; Chai Songshan; Deng Zhaoping; Zhou Bin

1993-09-01

The two-channel neutron boron meter is a continuous on-line measuring device to measure boron concentration of primary cooling liquid of reactors. The neutron-leakage-compensation method is taken in the measuring mechanism. In the primary measuring configuration, the mini-boron-water annulus and two-channel and central calibration loop are adopted. The calibration ring and constant-temperature of boron-water can be remotely controlled by secondary instruments. With the microcomputer data processing system the boron concentration is automatically measured and calibrated in on-line mode. The meter has many advantages such as high accuracy, fast response, multi-applications, high reliability and convenience

Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

Energy Technology Data Exchange (ETDEWEB)

Subhash Chandra

2008-05-30

The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysis of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.

Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

International Nuclear Information System (INIS)

Subhash, Chandra

2008-01-01

The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysis of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.

Lattice vibrations in α-boron

International Nuclear Information System (INIS)

Richter, W.

1976-01-01

α-rhombohedral boron is the simplest boron modification, with only 12 atoms per unit cell. The boron atoms are arranged in B 12 icosahedra, which are centered at the lattice points of a primitive rhombohedral lattice. The icosahedra are slightly deformed, as the five-fold symmetry of the ideal icosahedron is incompatible with any crystal structure. The lattice dynamics of α-boron are discussed in terms of the model developed by Weber and Thorpe. (Auth.)

Boron Fullerenes: A First-Principles Study

Directory of Open Access Journals (Sweden)

Gonzalez Szwacki Nevill

2007-01-01

Full Text Available AbstractA family of unusually stable boron cages was identified and examined using first-principles local-density functional method. The structure of the fullerenes is similar to that of the B12icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors, boron sheets, is made. We show that the most stable boron sheets are not necessarily precursors of very stable boron cages. Our finding is a step forward in the understanding of the structure of the recently produced boron nanotubes.

Neutron-gamma discrimination of boron loaded plastic scintillator

International Nuclear Information System (INIS)

Wang Dong; He Bin; Zhang Quanhu; Wu Chuangxin; Luo Zhonghui

2010-01-01

Boron loaded plastic scintillator could detect both fast neutrons thanks to hydrogen and thermal neutrons thanks to 10B. Both reactions have large cross sections, and results in high detection efficiency of incident neutrons. However, similar with other organic scintillators, boron loaded plastic scintillator is sensitive to gamma rays and neutrons. So gamma rays must be rejected from neutrons using their different behavior in the scintillator. In the present research zero crossing method was used to test neutron-gamma discrimination of BC454 boron loaded plastic scintillator. There are three Gaussian peaks in the time spectrum, they are corresponding to gamma rays, fast neutrons and flow neutrons respectively. Conclusion could be made that BC454 could clear discriminate slow neutrons and gamma, but the discrimination performance turns poor as the neutrons' energy becomes larger. (authors)

Separation of boron isotopes using NMG type anion exchange resin

International Nuclear Information System (INIS)

Itagaki, Takaharu; Kosuge, Masao; Fukuda, Junji; Fujii, Yasuhiko.

1992-01-01

Ion exchange separation of boron isotopes (B-10 and B-11) has been studied by using a special boron selective ion exchange resin; NMG (n-methyl glucamine)-type anion exchange resin. The resin has shown a large isotope separation coefficient of 1.02 at the experimental conditions of temperature, 80degC, and boric acid concentration, 0.2 M (mole/dm 3 ). Enriched B-10 (92%) was obtained after the migration of 1149 m by a recyclic operation of ion exchange columns in a merry-go-round method. (author)

Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

Energy Technology Data Exchange (ETDEWEB)

Nistor, L C [National Institute for Materials Physics, Bucharest (Romania); Nistor, S V [National Institute for Materials Physics, Bucharest (Romania); Dinca, G [Dacia Synthetic Diamonds Factory, Bucharest (Romania); Georgeoni, P [Dacia Synthetic Diamonds Factory, Bucharest (Romania); Landuyt, J van [University of Antwerpen - RUCA, EMAT, Antwerpen (Belgium); Manfredotti, C [Experimental Physics Department, University of Turin, Turin (Italy); Vittone, E [Experimental Physics Department, University of Turin, Turin (Italy)

2002-11-11

High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp{sup 3} bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 pm, 15 mJ m{sup -2} is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond.

Boron isotopes at the catchment scale, a new potential tool to infer critical zone processes.

Science.gov (United States)

Gaillardet, J.; Noireaux, J.; Braun, J. J.; Riotte, J.; Louvat, P.; Bouchez, J.; Lemarchand, D.; Muddu, S.; Mohan Kumar, M.; Candaudap, F.

2017-12-01

Boron is a mid-mass element that has two isotopes, 10B and 11B. These isotopes are largely fractioned by a number of chemical, biological and physical processes. Boron as a great affinity for clays and is useful for life, making it a double tracer of critical zone processes. This study focuses on the Mule Hole Critical Zone Observatory in South India. This is part of the French Research Infrastructure OZCAR and has benefited from the fruitful Indo-French collaboration (Indo-French Cell for Water Sciences) for more that 15 years. Boron and its isotopes were measured in the different compartment of the CZ in Mule Hole, vegetation, atmosphere, throughfall, soil, soil water, river water and compared to the behavior of other elements. The well constrained hydrology in Mule Hole allowed us to calculate the main fluxes affecting boron in the Critical Zone and came to the first order conclusion that the recycling of boron by vegetation is by far the most important flux within the system, reaching 15-20 times the catchment outlet flux. From an isotopic point of view, the total range of variation is measured between -3 ‰ and 77‰, with a bedrock value at 10‰ in classical delta unit, making boron a well suited tracer for constraining CZ processes. The flux of boron most enriched in heavy boron is the throughfall, showing the importance of biological processes in controlling the boron isotopic composition of the stream. Boron in soils in depleted in the heavy isotope but is enriched in boron compared to the bedrock, a surprising situation that we interpret as the legacy of a previous stage of transient weathering. These results indicate a strong decoupling between the behaviors of boron at the surface of the CZ and at depth.

Direct growth of hexagonal boron nitride/graphene heterostructures on cobalt foil substrates by plasma-assisted molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhongguang; Khanaki, Alireza; Tian, Hao; Zheng, Renjing; Suja, Mohammad; Liu, Jianlin, E-mail: jianlin@ece.ucr.edu [Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521 (United States); Zheng, Jian-Guo [Irvine Materials Research Institute, University of California, Irvine, California 92697-2800 (United States)

2016-07-25

Graphene/hexagonal boron nitride (G/h-BN) heterostructures have attracted a great deal of attention because of their exceptional properties and wide variety of potential applications in nanoelectronics. However, direct growth of large-area, high-quality, and stacked structures in a controllable and scalable way remains challenging. In this work, we demonstrate the synthesis of h-BN/graphene (h-BN/G) heterostructures on cobalt (Co) foil by sequential deposition of graphene and h-BN layers using plasma-assisted molecular beam epitaxy. It is found that the coverage of h-BN layers can be readily controlled on the epitaxial graphene by growth time. Large-area, uniform-quality, and multi-layer h-BN films on thin graphite layers were achieved. Based on an h-BN (5–6 nm)/G (26–27 nm) heterostructure, capacitor devices with Co(foil)/G/h-BN/Co(contact) configuration were fabricated to evaluate the dielectric properties of h-BN. The measured breakdown electric field showed a high value of ∼2.5–3.2 MV/cm. Both I-V and C-V characteristics indicate that the epitaxial h-BN film has good insulating characteristics.

The determination of boron in aluminium of high purity

International Nuclear Information System (INIS)

Cook, E.B.T.; Holan, H.

1977-01-01

A description is given of the investigations that led to the development of chemical methods for the determination of boron within the range 0,25 to 1,0 p.p.m. in aluminium of high purity. Methods were developed that incorporated fluorimetry, directly in solutions containing aluminium and after separation of boron by liquid-liquid extraction into 2-ethyl-1,3 hexanediol. A published spectrophotometric method, involving extraction of the BF 4 sup(-) complex with methylene blue into dichloroethane, was modified for application to alluminium samples. Details of this modified procedure and the fluorimetric-extraction procedure are appended. The precision of the methylene-blue method is about 6 percent relative and is recommended for precision and speed in preference to others. Separation of boron by distillation and spectrophotometric determination with curcumin gave low values in comparison with those obtained by the other methods. Agreement between the boron values obtained on the samples tested was good for the fluorimetric and methylene-blue spectrophotometric methods

Pumping experiment of water on B and LaB6 films with electron beam evaporator

International Nuclear Information System (INIS)

Mori, Takahiro; Hanaoka, Yutaka; Akaishi, Kenya; Kubota, Yusuke; Motojima, Osamu; Mushiaki, Motoi; Funato, Yasuyuki.

1992-10-01

Pumping characteristics of water vapor on boron and lanthanum hexaboride films formed with an electron beam evaporator have been investigated in high vacuum of a pressure region between 10 -4 and 10 -3 Pa. Measured initial maximum pumping speeds of water for fresh B and LaB 6 films on substrates with a deposition amount from 2.3 x 10 21 to 6.7 x 10 21 molecules·m -2 are 3.2 ∼ 4.9 m 3 ·s -1 ·m -2 , and maximum saturation amounts of adsorbed water on these films are 2.9 x 10 20 ∼ 1.3 x 10 21 H 2 O molecules·m -2 . (author)

Boron biodistribution study in colorectal liver metastases patients in Argentina

International Nuclear Information System (INIS)

Cardoso, J.; Nievas, S.; Pereira, M.; Schwint, A.; Trivillin, V.; Pozzi, E.; Heber, E.; Monti Hughes, A.; Sanchez, P.; Bumaschny, E.; Itoiz, M.; Liberman, S.

2009-01-01

Ex-situ BNCT for multifocal unresectable liver metastases employing whole or partial autograft techniques requires knowledge of boron concentrations in healthy liver and metastases following perfusion and immersion in Wisconsin solution (W), the procedure employed for organ preservation during ex-situ irradiation. Measurements of boron concentration in blood, liver and metastases following an intravenous infusion of BPA-F in five colorectal liver metastases patients scheduled for surgery were performed. Tissue samples were evaluated for boron content pre and post perfusion and immersion in W. Complementary histological studies were performed. The data showed a dose-dependent BPA uptake in liver, a boron concentration ratio liver/blood close to 1 and a wide spread in the metastases/liver concentration ratios in the range 0.8-3.6, partially attributable to histological variations between samples. Based on the boron concentrations and dose considerations (liver≤ 15 Gy-Eq and tumor≥40 Gy-Eq) at the RA-3 thermal neutron facility (mean flux of about (6±1)x10 9 n cm -2 s -1 ), ex-situ treatment of liver metastases at RA-3 would be feasible.

Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems

Energy Technology Data Exchange (ETDEWEB)

Ping, Qingyun [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Abu-Reesh, Ibrahim M. [Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); He, Zhen, E-mail: zhenhe@vt.edu [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

2016-11-01

Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level < 2 mg L{sup −} {sup 1}. The ratio between the anolyte and the catholyte flow rates should be kept > 22.2 in order to avoid boron accumulation in the anolyte effluent. - Highlights: • Mathematical models are developed to understand boron removal in BES. • Boron removal can be driven by electromigration induced by current generation. • Diffusion induced by a salt concentration gradient also contributes to boron removal. • Osmosis and current driven convection transport play diverse roles in different BES.

The irradiation behaviour of boron carbide/graphite between 800 and 1,1000C

International Nuclear Information System (INIS)

Hattenbach, K.; Hilgendorff, W.; Weiler, K.; Zimmermann, H.U.

1975-01-01

64 samples of boron carbide/graphite, a material used as burnable poison in high temperature reactors, were irradiated at temperatures between 800 and 1,100 0 C up to a fluence of 1-2 x 10 20 nvt. The following post-investigations were extended to dimensional measurements to determime a possible swelling or shrinking of the pellet, corrosion tests in completely desalinated water at 300 0 C, preparation of metallographic microsections to check for crack formation, determination of the helium hold back power and the thus involved gas chromatic analysis, as well as burn-up determinations by determining the boron 10/boron 11 ratio and the lithium concentration. (orig./LN) [de

Effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy

Science.gov (United States)

Masunaga, S; Sakurai, Y; Tanaka, H; Suzuki, M; Liu, Y; Kondo, N; Maruhashi, A; Kinashi, Y; Ono, K

2012-01-01

Objectives To evaluate the effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy (BNCT) by measuring the response of intratumour quiescent (Q) cells. Methods B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumours received reactor thermal neutron beam irradiation following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)] in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation. Results BPA-BNCT increased the sensitivity of the total tumour cell population more than BSH-BNCT. However, the sensitivity of Q cells treated with BPA was lower than that of BSH-treated Q cells. With or without a 10B–carrier, MTH enhanced the sensitivity of the Q cell population. Without irradiation, nicotinamide treatment decreased the number of lung metastases. With irradiation, BPA-BNCT, especially in combination with nicotinamide treatment, showed the potential to reduce the number of metastases more than BSH-BNCT. Conclusion BSH-BNCT in combination with MTH improves local tumour control, while BPA-BNCT in combination with nicotinamide may reduce the number of lung metastases. PMID:22391496

High strain amount in recessed junctions induced by selectively deposited boron-doped SiGe layers

Energy Technology Data Exchange (ETDEWEB)

Radamson, H.H. [School of Information and Communication Technology, KTH (Royal Institute of Technology) Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)], E-mail: rad@kth.se; Kolahdouz, M.; Ghandi, R.; Ostling, M. [School of Information and Communication Technology, KTH (Royal Institute of Technology) Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)

2008-12-05

This work presents the selective epitaxial growth (SEG) of Si{sub 1-x}Ge{sub x} (x = 0.15-0.315) layers with high amount of boron (1 x 10{sup 20}-1 x 10{sup 21} cm{sup -3}) in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. The influence of the growth rate and strain on boron incorporation has been studied. A focus has been made on the strain distribution and boron incorporation in SEG of SiGe layers.

Boron supplementation in broiler diets

Directory of Open Access Journals (Sweden)

EJ Fassani

2004-12-01

Full Text Available Boron supplementation in broiler feed is not a routine practice. However, some reports suggest a positive effect of boron on performance. This study assessed the effects of boron supplementation on broiler performance. Diets were based on maize and soybean meal, using boric acid P.A. as boron source. Six supplementation levels (0, 30, 60, 90, 120 and 150 ppm were evaluated using 1,440 one-day old males housed at a density of 30 chickens in each of 48 experimental plots of 3m². A completely randomized block design was used with 8 replicates. Feed intake, weight gain and feed conversion were assessed in the periods from 1 to 7 days, 1 to 21 days and 1 to 42 days of age, and viability was evaluated for the total 42-day rearing period. No performance variable was affected by boron supplementation (p>0.05 in the period from 1 to 7 days. The regression analysis indicated an ideal level of 37.4 ppm of boron for weight gain from 1 to 21 days (p0.05, although feed intake was reduced linearly with increased boron levels (p0.05. Ash and calcium percentages in the tibias of broilers and viability in the total rearing period were not affected by boron supplementation (p>0.05.

Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.

Science.gov (United States)

Hakki, Sema S; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Kerimoglu, Ulku; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H

2013-04-01

An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet. Copyright © 2012 Elsevier GmbH. All rights reserved.

Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

Science.gov (United States)

Blue, Thomas E; Yanch, Jacquelyn C

2003-01-01

This paper reviews the development of low-energy light ion accelerator-based neutron sources (ABNSs) for the treatment of brain tumors through an intact scalp and skull using boron neutron capture therapy (BNCT). A major advantage of an ABNS for BNCT over reactor-based neutron sources is the potential for siting within a hospital. Consequently, light-ion accelerators that are injectors to larger machines in high-energy physics facilities are not considered. An ABNS for BNCT is composed of: (1) the accelerator hardware for producing a high current charged particle beam, (2) an appropriate neutron-producing target and target heat removal system (HRS), and (3) a moderator/reflector assembly to render the flux energy spectrum of neutrons produced in the target suitable for patient irradiation. As a consequence of the efforts of researchers throughout the world, progress has been made on the design, manufacture, and testing of these three major components. Although an ABNS facility has not yet been built that has optimally assembled these three components, the feasibility of clinically useful ABNSs has been clearly established. Both electrostatic and radio frequency linear accelerators of reasonable cost (approximately 1.5 M dollars) appear to be capable of producing charged particle beams, with combinations of accelerated particle energy (a few MeV) and beam currents (approximately 10 mA) that are suitable for a hospital-based ABNS for BNCT. The specific accelerator performance requirements depend upon the charged particle reaction by which neutrons are produced in the target and the clinical requirements for neutron field quality and intensity. The accelerator performance requirements are more demanding for beryllium than for lithium as a target. However, beryllium targets are more easily cooled. The accelerator performance requirements are also more demanding for greater neutron field quality and intensity. Target HRSs that are based on submerged-jet impingement and

The effect of boron additions on irradiation-induced order changes in Ni3Al intermetallic compounds

International Nuclear Information System (INIS)

Njah, N.; Gilbon, D.; Dimitrov, O.

1995-01-01

The effects of boron additions (0.1 wt%) on the kinetics of atomic order changes in a Ni 76 Al 24 intermetallic compound, under 1 MeV electron irradiation, were investigated at temperatures of 293 K and 410 K and displacement rates of 0.09 x 10 -3 to 4.7 x 10 -3 dpa.s -1 . In these irradiation conditions, a state of residual order was obtained for long irradiation times, characterized by a steady state order parameter S∞; it corresponds to a competition between two opposite features: irradiation disordering and thermal reordering enhanced by irradiation. Boron additions did not affect the efficiency of irradiation-induced disordering: the disordering cross-section (or, equivalently, the number of replacements per displacement var-epsilon) were comparable with and without a boron addition. By contrast, the S∞ values at 293 K were much lower in the alloy containing boron. Since boron does not change the disordering rate, the large difference between the values obtained in undoped and in boron-doped alloys shows that the reordering rate is strongly reduced by the presence of boron. Thus, boron modifies the mobility of the defects responsible for the irradiation-enhanced diffusion. The data on dislocation-loop size and the reordering kinetics suggest that vacancies are trapped by boron at low temperatures and immobilized, probably by the formation of a boron-vacancy complex. The effect becomes weaker at higher displacement rates and higher temperatures, probably due to the boron-vacancy complexes becoming unstable. It is proposed that two different reordering mechanisms may be operative at 293 K, according to the presence of boron: reordering is promoted by vacancy migration in the Ni 76 Al 24 alloy, whereas in the Ni 76 Al 24 (0.1 wt%B) alloy, it is promoted by the migration of split-interstitials or/and of low-mobility vacancy-boron complexes

Optimization of the irradiation beam in the BNCT research facility at IEA-R1 reactor

International Nuclear Information System (INIS)

Castro, Vinicius Alexandre de

2014-01-01

Boron Neutron Capture Therapy (BNCT) is a radiotherapeutic technique for the treatment of some types of cancer whose useful energy comes from a nuclear reaction that occurs when thermal neutron impinges upon a Boron-10 atom. In Brazil there is a research facility built along the beam hole number 3 of the IEA-R1 research reactor at IPEN, which was designed to perform BNCT research experiments. For a good performance of the technique, the irradiation beam should be mostly composed of thermal neutrons with a minimum as possible gamma and above thermal neutron components. This work aims to monitor and evaluate the irradiation beam on the sample irradiation position through the use of activation detectors (activation foils) and also to propose, through simulation using the radiation transport code, MCNP, new sets of moderators and filters which shall deliver better irradiation fields at the irradiation sample position In this work, a simulation methodology, based on a MCNP card, known as wwg (weight window generation) was studied, and the neutron energy spectrum has been experimentally discriminated at 5 energy ranges by using a new set o activation foils. It also has been concluded that the BNCT research facility has the required thermal neutron flux to perform studies in the area and it has a great potential for improvement for tailoring the irradiation field. (author)

Synovectomy by neutron capture in boron

International Nuclear Information System (INIS)

Vega C, H.R.

2002-01-01

The rheumatoid arthritis is an illness which affect approximately at 3% of the World population. This illness is characterized by the inflammation of the joints which reduces the quality of life and the productivity of the patients. Since, it is an autoimmune illness, the inflammation is due to the overproduction of synovial liquid by the increase in the quantity of synoviocytes. The rheumatoid arthritis does not have a definitive recovery and the patients have three options of treatment: the use of drugs, the surgery and the radio synovectomy. The synovectomy by neutron capture in Boron is a novel proposal of treatment of the rheumatoid arthritis that consists in using a charged compound with Boron 10 that is preferently incorporated in the synoviocytes and to a less extent in the rest of surrounding tissues of the joint. Then, the joint is exposed to a thermal neutron field that induces the reaction (n, α) in the 10 B. the products of this reaction place their energy inside synoviocytes producing their reduction and therefore the reduction of the joint inflammation. Since it is a novel procedure, the synovectomy by neutron capture in boron has two problems: the source design and the design of the adequate drug. In this work it has been realized a Monte Carlo study with the purpose to design a moderating medium that with a 239 Pu Be source in its center, produces a thermal neutron field. With the produced neutron spectra, the neutrons spectra and neutron doses were calculated in different sites inside a model of knee joint. In Monte Carlo studies it is necessary to know the elemental composition of all the joint components, for the case of synovia and the synovial liquid this information does not exist in such way that it is supposed that its composition is equal than the water. In this work also it has been calculated the kerma factors by neutrons of synovia and the synovial liquid supposing that their elemental composition are similar to the blood tissue

Carborane derivative development for boron neutron capture therapy. Final report

International Nuclear Information System (INIS)

Barnum, Beverly A.; Yan Hao; Moore, Roger; Hawthorne, M. Frederick; Baum, Kurt

1999-01-01

Boron Neutron Capture Therapy [BNCT] is a binary method of cancer therapy based on the capture of neutrons by a boron-10 atom [ 10 B]. Cytotoxic 7 Li nuclei and α-particles are emitted, with a range in tissue of 9 and 5 microm, respectively, about one cell diameter. The major obstacle to clinically viable BNCT is the selective localization of 5-30 ppm 10 B in tumor cells required for effective therapy. A promising approach to BNCT is based on hydrophilic boron-rich oligomeric phosphate diesters, or ''trailers'' that have been shown to concentrate selectively in tumor tissue. Examples of these compounds were prepared previously at high cost using an automated DNA synthesizer. Direct synthesis methods are needed for the production of gram-scale quantities for further biological evaluation. The work accomplished as a result of the collaboration between Fluorochem, Inc. and UCLA demonstrates that short oligomers containing at least five carborane units with four phosphodiester linkages can be prepared in substantial quantities. This work was accomplished by the application of standard phosphoramidite coupling chemistry

Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

Energy Technology Data Exchange (ETDEWEB)

Zobelli, A

2007-10-15

The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

International Nuclear Information System (INIS)

Zobelli, A.

2007-10-01

The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

Nuclear magnetic resonance spectroscopy of boron compounds containing two-, three- and four-coordinate boron

International Nuclear Information System (INIS)

Wrackmeyer, B.

1988-01-01

The influence of boron chemistry on various areas of research in inorganic, organic and theoretical chemistry is well documented. In fact, many models presently employed to describe chemical bonding in general can be traced to attempts to understand bonding in boranes. The confirmation of many theoretical predictions in boron chemistry relies on direct and indirect structural information provided by various physical methods that - fortunately - became available almost at the same rate as that with which the interest in boron compounds was growing. Clearly, there has always been a strong link between the interest in synthesis and the application of physical methods. As in many other areas of chemistry, developments in boron chemistry have been greatly accelerated by NMR. 11 B NMR has been at the center of interest from the beginning, accompanied by routine 1 H NMR measurements, and occasional 14 N, 19 F and 31 P NMR work. In the last 12 years, we have seen an increasing number of 13 C NMR studies of boron compounds. The availability of multinuclear facilities for PFT NMR spectrometers stimulates the measurement of the NMR spectra of other nuclei, like 29 Si, 119 Sn or other metals, in order to obtain additional information. This paper is intended to serve several purposes: to update previous reviews on 11 B NMR of boron compounds, to demonstrate some applications of multinuclear NMR to boron chemistry; to attempt to incorporate new NMR parameters into the known data set; and to summarize the experimental facts required for obtaining the maximum information from NMR studies on boron compounds

Radiation hardening of MOS devices by boron

International Nuclear Information System (INIS)

Danchenko, V.

1975-01-01

A novel technique is disclosed for radiation hardening of MOS devices and specifically for stabilizing the gate threshold potential at room temperature of a radiation subjected MOS field-effect device of the type having a semiconductor substrate, an insulating layer of oxide on the substrate, and a gate electrode disposed on the insulating layer. In the preferred embodiment, the novel inventive technique contemplates the introduction of boron into the insulating oxide, the boron being introduced within a layer of the oxide of about 100A to 300A thickness immediately adjacent the semiconductor-insulator interface. The concentration of boron in the oxide layer is preferably maintained on the order of 10 atoms/ cm 3 . The novel technique serves to reduce and substantially annihilate radiation induced positive gate charge accumulations, which accumulations, if not eliminated, would cause shifting of the gate threshold potential of a radiation subjected MOS device, and thus render the device unstable and/or inoperative. (auth)

Frequency mixing in boron carbide laser ablation plasmas

Science.gov (United States)

Oujja, M.; Benítez-Cañete, A.; Sanz, M.; Lopez-Quintas, I.; Martín, M.; de Nalda, R.; Castillejo, M.

2015-05-01

Nonlinear frequency mixing induced by a bichromatic field (1064 nm + 532 nm obtained from a Q-switched Nd:YAG laser) in a boron carbide (B4C) plasma generated through laser ablation under vacuum is explored. A UV beam at the frequency of the fourth harmonic of the fundamental frequency (266 nm) was generated. The dependence of the efficiency of the process as function of the intensities of the driving lasers differs from the expected behavior for four-wave mixing, and point toward a six-wave mixing process. The frequency mixing process was strongly favored for parallel polarizations of the two driving beams. Through spatiotemporal mapping, the conditions for maximum efficiency were found for a significant delay from the ablation event (200 ns), when the medium is expected to be a low-ionized plasma. No late components of the harmonic signal were detected, indicating a largely atomized medium.

Beam Characterization of 10-MV Photon Beam from Medical Linear Accelerator without Flattening Filter.

Science.gov (United States)

Shimozato, Tomohiro; Aoyama, Yuichi; Matsunaga, Takuma; Tabushi, Katsuyoshi

2017-01-01

This work investigated the dosimetric properties of a 10-MV photon beam emitted from a medical linear accelerator (linac) with no flattening filter (FF). The aim of this study is to analyze the radiation fluence and energy emitted from the flattening filter free (FFF) linac using Monte Carlo (MC) simulations. The FFF linac was created by removing the FF from a linac in clinical use. Measurements of the depth dose (DD) and the off-axis profile were performed using a three-dimensional water phantom with an ionization chamber. A MC simulation for a 10-MV photon beam from this FFF linac was performed using the BEAMnrc code. The off-axis profiles for the FFF linac exhibited a chevron-like distribution, and the dose outside the irradiation field was found to be lower for the FFF linac than for a linac with an FF (FF linac). The DD curves for the FFF linac included many contaminant electrons in the build-up region. Therefore, for clinical use, a metal filter is additionally required to reduce the effects of the electron contamination. The mean energy of the FFF linac was found to be lower than that of the FF linac owing to the absence of beam hardening caused by the FF.

A Micromegas Detector for Neutron Beam Imaging at the n_TOF Facility at CERN

CERN Document Server

Belloni, F; Berthoumieux, E; Calviani, M; Chiaveri, E; Colonna, N; Giomataris, Y; Guerrero, C; Gunsing, F; Iguaz, F J; Kebbiri, M; Pancin, J; Papaevangelou, T; Tsinganis, A; Vlachoudis, V; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Cortés, G; Corté-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Langer, C; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Marítnez, T; Massimi, C; Mastinu, P F; Mastromarco, M; Meaze, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A J M; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T J; Žugec, P

2014-01-01

Micromegas (Micro-MEsh Gaseous Structure) detectors are gas detectors consisting of a stack of one ionization and one proportional chamber. A micromesh separates the two communicating regions, where two different electric fields establish respectively a charge drift and a charge multiplication regime. The n\\_TOF facility at CERN provides a white neutron beam (from thermal up to GeV neutrons) for neutron induced cross section measurements. These measurements need a perfect knowlodge of the incident neutron beam, in particular regarding its spatial profile. A position sensitive micromegas detector equipped with a B-10 based neutron/charged particle converter has been extensively used at the n\\_TOF facility for characterizing the neutron beam profile and extracting the beam interception factor for samples of different size. The boron converter allowed to scan the energy region of interest for neutron induced capture reactions as a function of the neutron energy, determined by the time of flight. Experimental ...

Nuclear-physical techniques for determination of boron distribution in pure materials

International Nuclear Information System (INIS)

Kadirova, M.; Jumaev, N.; Simakhin, Yu.F.; Idrisov, Kh.; Usmanova, M.M.

2001-01-01

To study deep boron diffusion in the complex silicon structures, consisting of interchange boron doping layers of mono- and polycrystalline silicon, separated by oxide films a technique of sidelong section by using Solid State Nuclear Track Detector (SSNTD) has been elaborated. The boron distribution determination technique is based on the detection of alpha particles from the 10B(n, )7Li reaction with cellulose nitrate film. The etched track registering cellulose nitrate film show the structure image magnified 1/sin fold. Boron concentration defined by density of the etched pits appearing on the film surface. An optical microscope analysis of the sample track-mapping image is realized by examination with closely spaced ( l < x/sin ) and largely spaced ( l x/sin ) movements. All these elaborated techniques can be used to investigate other solid matrix

Cell cycle dependence of boron uptake in various boron compounds used for neutron capture therapy

International Nuclear Information System (INIS)

Yoshida, F.; Matsumura, A.; Shibata, Y.; Yamamoto, T.; Nose, T.; Okumura, M.

2000-01-01

In neutron capture therapy, it is important that the tumor take boron in selectively. Furthermore, it is ideal when the uptake is equal in each tumor cell. Some indirect proof of differences in boron uptake among neoplastic cell cycles has been documented. However, no investigation has yet measured boron uptake directly. Using flow cytometry, in the present study cells were sorted by G0/G1 phase and G2/M phase, and the boron concentration of each fraction was measured with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results were that BSH (sodiumborocaptate) and BPA (p-boronophenylalanine) had higher rates of boron uptake in the G2/M group than in the G0/G1 group. However, in BPA the difference was more prominent, which revealed a 2.2-3.3 times higher uptake of boron in the G2/M group than in the G0/G1 group. (author)

Neutron autoradiography imaging of selective boron uptake in human metastatic tumours

Energy Technology Data Exchange (ETDEWEB)

Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Via Bassi 6, Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, Via Bassi 6, Pavia (Italy)], E-mail: saverio.altieri@pv.infn.it; Bortolussi, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Via Bassi 6, Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, Via Bassi 6, Pavia (Italy); Bruschi, P.; Chiari, P.; Fossati, F.; Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Via Bassi 6, Pavia (Italy); Prati, U.; Roveda, L. [Unit of cancer surgery, Cancer Center of Excellence, Foundation T. Campanella, Catanzaro (Italy); Zonta, A.; Zonta, C.; Ferrari, C.; Clerici, A. [Department of Surgery, University of Pavia, Piazza Botta, Pavia (Italy); Nano, R. [Department of Animal Biology, University of Pavia, Piazza Botta, Pavia (Italy); Pinelli, T. [Department of Nuclear and Theoretical Physics, University of Pavia, Via Bassi 6, Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, Via Bassi 6, Pavia (Italy)

2008-12-15

The ability to selectively hit the tumour cells is an essential characteristic of an anti-tumour therapy. In boron neutron capture therapy (BNCT) this characteristic is based on the selective uptake of {sup 10}B in the tumour cells with respect to normal tissues. An important step in the BNCT planning is the measurement of the boron concentration in the tissue samples, both tumour and healthy. When the tumour is spread through the healthy tissue, as in the case of metastases, the knowledge of the different kinds of tissues in the sample being analysed is crucial. If the percentage of tumour and normal tissues cannot be evaluated, the obtained concentration is a mean value depending on the composition of the different samples being measured. In this case an imaging method that could give information both on the morphology and on the spatial distribution of boron concentration in the sample would be a fundamental support. In this paper, the results of the boron uptake analysis in the tumour and in the healthy samples taken from human livers after boron phenylalanine (BPA) infusion are shown; boron imaging was performed using neutron autoradiography.

Strong field physics and QED experiments with ELI-NP 2×10PW laser beams

Energy Technology Data Exchange (ETDEWEB)

Turcu, I. C. E., E-mail: Edmond.Turcu@eli-np.ro; Balascuta, S., E-mail: Edmond.Turcu@eli-np.ro; Negoita, F., E-mail: Edmond.Turcu@eli-np.ro [National Institute for Physics and Nuclear Engineering, ELI-NP, Str. Reactorului, nr. 30, P.O.Box MG-6, Bucharest-Magurele (Romania); Jaroszynski, D.; McKenna, P. [University of Strathclyde, Scottish Universities Physics Alliance (SUPA), Glasgow G4 0NG, Scotland (United Kingdom)

2015-02-24

The ELI-NP facility will focus a 10 PW pulsed laser beam at intensities of ∼10{sup 23} W/cm{sup 2} for the first time, enabling investigation of the new physical phenomena at the interfaces of plasma, nuclear and particle physics. The electric field in the laser focus has a maximum value of ∼10{sup 15} V/m at such laser intensities. In the ELI-NP Experimental Area E6, we propose the study of Radiation Reaction, Strong Field Quantum Electrodynamics (QED) effects and resulting production of Ultra-bright Sources of Gamma-rays which could be used for nuclear activation. Two powerful, synchronized 10 PW laser beams will be focused in the E6 Interaction Chamber on either gas or solid targets. One 10 PW beam is the Pump-beam and the other is the Probe-beam. The focused Pump beam accelerates the electrons to relativistic energies. The accelerated electron bunches interact with the very high electro-magnetic field of the focused Probe beam. The layout of the experimental area E6 will be presented with several options for the experimental configurations.

Differentiation in boron distribution in adult male and female rats' normal brain: A BNCT approach

International Nuclear Information System (INIS)

Goodarzi, Samereh; Pazirandeh, Ali; Jameie, Seyed Behnamedin; Baghban Khojasteh, Nasrin

2012-01-01

Boron distribution in adult male and female rats' normal brain after boron carrier injection (0.005 g Boric Acid+0.005 g Borax+10 ml distilled water, pH: 7.4) was studied in this research. Coronal sections of control and trial animal tissue samples were irradiated with thermal neutrons. Using alpha autoradiography, significant differences in boron concentration were seen in forebrain, midbrain and hindbrain sections of male and female animal groups with the highest value, four hours after boron compound injection. - Highlights: ► Boron distribution in male and female rats' normal brain was studied in this research. ► Coronal sections of animal tissue samples were irradiated with thermal neutrons. ► Alpha and Lithium tracks were counted using alpha autoradiography. ► Different boron concentration was seen in brain sections of male and female rats. ► The highest boron concentration was seen in 4 h after boron compound injection.

Alleviation of Boron Stress through Plant Derived Smoke Extracts in Sorghum bicolor

Directory of Open Access Journals (Sweden)

Pirzada Khan

2014-08-01

Full Text Available Boron is an essential micronutrient necessary for plant growth at optimum concentration. However, at high concentrations boron affects plant growth and is toxic to cells. Aqueous extract of plant-derived smoke has been used as a growth regulator for the last two decades to improve seed germination and seedling vigor. It has been established that plant-derived smoke possesses some compounds that act like plant growth hormones. The present research was the first comprehensive attempt to investigate the alleviation of boron stress with plant-derived smoke aqueous extract on Sorghum (Sorghum bicolor seed. Smoke extracts of five plants, i.e. Cymbopogon jwarancusa, Eucalyptus camaldulensis, Peganum harmala, Datura alba and Melia azedarach each with six dilutions (Concentrated, 1:100, 1:200, 1:300, 1:400 and 1:500 were used. While boron solutions at concentrations of 5, 10, 15, 20 and 25 ppm were used for stress. Among the dilutions of smoke, 1:500 of E. camaldulensis significantly increased germination percentage, root and shoot length, number of secondary roots and fresh weight of root and shoot while, boron stress reduced growth of Sorghum. It was observed that combined effect of boron solution and E. camaldulensis smoke extract overcome inhibition and significantly improved plant growth. Present research work investigated that the smoke solution has the potential to alleviate boron toxicity by reducing the uptake of boron by maintaining integrity of plant cell wall. The present investigation suggested that plant derived smoke has the potential to alleviate boron stress and can be used to overcome yield losses caused by boron stress to plants.

Boron-Loaded Silicone Rubber Scintillators

Energy Technology Data Exchange (ETDEWEB)

Bell, Z.W.; Maya, L.; Brown, G.M.; Sloop, F.V.Jr

2003-05-12

Silicone rubber received attention as an alternative to polyvinyltoluene in applications in which the scintillator is exposed to high doses because of the increased resistance of the rubber to the formation of blue-absorbing color centers. Work by Bowen, et al., and Harmon, et al., demonstrated their properties under gamma/x-ray irradiation, and Bell, et al. have shown their response to thermal neutrons. This last work, however, provided an example of a silicone in which both the boron and the scintillator were contained in the rubber as solutes, a formulation which led to the precipitation of solids and sublimation of the boron component. In the present work we describe a scintillator in which the boron is chemically bonded to the siloxane and so avoids the problem of precipitation and loss of boron to sublimation. Material containing up to 18% boron, by weight, was prepared, mounted on photomultipliers, and exposed to both neutron and gamma fluxes. Pulse height spectra showing the neutron and photon response were obtained, and although the light output was found to be much poorer than from samples in which boron was dissolved, the higher boron concentrations enabled essentially 100% neutron absorption in only a few millimeters' thickness of rubber.

Boron Removal from Seawater by Thin-Film Composite Reverse Osmosis Membranes

KAUST Repository

Al Sunbul, Yasmeen

2018-04-01

Reverse Osmosis membranes have been successfully proven to remove almost 99% of chemicals dissolved in seawater. However, removal of certain trace elements, such as boron is challenging and relatively low for seawater reverse osmosis desalination plants compared to thermal desalination plants. Boron is naturally occurring and is present in seawater at an average concentration of 4.5-5 mg/L. While boron is a vital element, its toxicity has been proven on crops, animals and possibly humans. Additionally, boron should be removed to comply with the current guideline value of 0.5 mg/L, for drinking water, issued by the World Health Organization (WHO), which is barely attained by a single-pass process seawater reverse osmosis plant. Currently, multipass reverse osmosis membrane operations with pH modifications are the only valid method for boron removal. However, this is not economically efficient as it requires higher energy and chemicals consumptions. The objective of this study was to investigate boron removal by commercial TFC RO membranes in addition to custom-made KAUST-synthesized TFC membrane. Five membrane samples were examined: Toray, Sepro, Koch, and KAUST in-house synthesized membrane. Three different feed pH conditions were used: pH6, pH8, and pH10. Filtration experiments were conducted in two parts. In experiment 1, all five membranes were examined for boron rejection in a dead-end permeation system, whereas in experiment 2 the two membranes with the highest boron rejection from experiment 1 were tested in a cross-flow system. Permeate and feed samples were taken continuously and analyzed for boron concentration, rejection calculation. Membrane surfaces were characterized according to hydrophilicity, roughness and surface charge. The results showed for all the tested membranes that boron rejection increased as the feed pH increased. KAUST, defect-free TFC, showed the highest performance for boron rejection for all pH conditions, although, it shows the

Spectrophotometric determination of boron in ammonium diuranate and interference studies

International Nuclear Information System (INIS)

Ramanjaneyulu, P.S.; Raman, V.A.; Sayi, Y.S.; Ramakumar, K.L.

2005-01-01

This paper describes determination of boron in ammonium diuranate by spectrophotometry employing curcumin as a complexing agent after extraction of boron with 2-ethyl hexane 1,3 diol. Two diluents namely ethyl alcohol (EtOH) and N,N-dimethyl formamide (DMF) were investigated for the preparation of final solution. It was observed that the blank is less with DMF presumably due to higher extent of deprotonation of uncomplexed curcumin. The detection limits of method for 25 and 10 ml dilution are 20 ng and 10 ng respectively. Interference studies for several cation and anion species like Al, Cr, Mg, Ca, Fe, Mn, Mo, F, W, NO, and different amount of 10% EHD in CHCl 3 are also discussed. (author)

Determination of boron in nuclear materials at subppm levels by high pressure liquid chromatography (HPLC)

International Nuclear Information System (INIS)

Rao, Radhika M.; Aggarwal, S.K.

2002-11-01

Experiments were conducted for the determination of boron in U 3 O 8 powder, aluminium metal and milliQ water using dynamically modified Reversed Phase High Pressure Liquid Chromatography (RP-HPLC) and using two precolumn chromogenic agents viz. chromotropic acid and curcumin for complexing boron. The complex was separated from the excess of reagent and determined by HPLC. When present in subppm levels, chromotropic acid was used successfully only for determination boron in water samples. For determination of boron at subppm levels in uranium and aluminium samples, curcumin was used as the precolumn chromogenic agent. The boron curcumin complex (rosocyanin) was formed after extraction of boron with 2-ethyl-l, 3-hexane diol (EHD). The rosocyanin complex was then separated from excess curcumin by displacement chromatography. Linear calibration curves for boron amounts in the range of 0.02 μg to 0.5 μg were developed with correlation coefficients varying from 0.997 to 0.999 and were used for the determination of boron in aluminium and uranium samples. Precision of about 10% was achieved in samples containing less than 1 ppmw of boron. Detection limit of this method is 0.01 μg boron. (author)

A system to deposit boron films (boronization) in the DIII-D tokamak

International Nuclear Information System (INIS)

Hodapp, T.R.; Jackson, G.L.; Phillips, J.; Holtrop, K.L.; Peterson, P.L.; Winters, J.

1992-01-01

A system has been added to the DIII-D tokamak to coat its plasma facing surfaces with a film of boron using diborane gas. The system includes special health and safety equipment for handling the diborane gas which is toxic and inflammable. The purpose f the boron film is to reduce the levels of impurity atoms in the DIII-D plasmas. Experiments following the application of the boron film in DIII-D have led to significant reductions in plasma impurity levels and the observation of a new, very high confinement regime

New Pathways and Metrics for Enhanced, Reversible Hydrogen Storage in Boron-Doped Carbon Nanospaces

Energy Technology Data Exchange (ETDEWEB)

Pfeifer, Peter [University of Missouri; Wexler, Carlos [University of Missouri; Hawthorne, M. Frederick [University of Missouri; Lee, Mark W. [University of Missouri; Jalistegi, Satish S. [University of Missouri

2014-08-14

This project, since its start in 2007—entitled “Networks of boron-doped carbon nanopores for low-pressure reversible hydrogen storage” (2007-10) and “New pathways and metrics for enhanced, reversible hydrogen storage in boron-doped carbon nanospaces” (2010-13)—is in support of the DOE's National Hydrogen Storage Project, as part of the DOE Hydrogen and Fuel Cells Program’s comprehensive efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization and market acceptance of hydrogen powered vehicles. Storing sufficient hydrogen on board a wide range of vehicle platforms, at energy densities comparable to gasoline, without compromising passenger or cargo space, remains an outstanding technical challenge. Of the main three thrust areas in 2007—metal hydrides, chemical hydrogen storage, and sorption-based hydrogen storage—sorption-based storage, i.e., storage of molecular hydrogen by adsorption on high-surface-area materials (carbons, metal-organic frameworks, and other porous organic networks), has emerged as the most promising path toward achieving the 2017 DOE storage targets of 0.055 kg H2/kg system (“5.5 wt%”) and 0.040 kg H2/liter system. The objective of the project is to develop high-surface-area carbon materials that are boron-doped by incorporation of boron into the carbon lattice at the outset, i.e., during the synthesis of the material. The rationale for boron-doping is the prediction that boron atoms in carbon will raise the binding energy of hydro- gen from 4-5 kJ/mol on the undoped surface to 10-14 kJ/mol on a doped surface, and accordingly the hydro- gen storage capacity of the material. The mechanism for the increase in binding energy is electron donation from H2 to electron-deficient B atoms, in the form of sp2 boron-carbon bonds. Our team is proud to have

Use of linear programming to obtain an optimum, multi-beam treatment plan in BNCT

International Nuclear Information System (INIS)

Nievaart, Sander; Moss, Ray; Sauerwein, Wolfgang; Wittig, Andrea

2006-01-01

For BNCT of melanoma metastases in the brain, it has been necessary to calculate the dose distributions in the patient for dozens of possible neutron beams and then to combine manually the different beams by individually weighting and adding them. This time consuming approach eventually gave the required treatment plan, which satisfied the prescription dose. However, by linear optimisation with the Simplex method, the optimum weights for a set of beams can be determined mathematically. The objective function to maximise is the minimum averaged physical boron dose in one certain lesion for every set of beams. The maximisation of this objective function is performed under the constraints of certain maximum and minimum dose limits in the organs at risk and lesions respectively and restricting the set of weighted beams to deliver an average total weighted dose of 7 Gy in the brain. After iteration, by using the constraint set for the minimum dose in the lesions as a variable and performed for all combinations of the neutron beams, the optimum beams and weights are found for each treatment. As a preliminary result, the total irradiation time decreased by more than 30%, which is advantageous regarding both the pharmacokinetics of the boron in the patient and patient comfort. (author)

Investigation of boron extraction process with aid magnesium hydroxide from mother liquor of boron production

International Nuclear Information System (INIS)

Balapanova, B.S.; Zhajmina, R.E.; Serazetdinov, D.Z.

1988-01-01

Conditions of boron - magnesium concentrate preparation from mother liquor by coprecipitation of borate - ions by magnesium hydroxide are investigated. It is shown that boron - magnesium concentrate and products of its heat treatment at 100 - 500 deg C in water are dissolved partially, and in ammonium citrate - practically completely. Suppositions are made on the composition of the product prepared, on the the structure of its crystal lattice and the processes taking place in it during heat treatment. The conclusion is made on the perspectiveness of processing of mother liquor of boron industry for boron - magnesium concentrate

Crossed Molecular Beams Investigations on the Dynamics and Energetics of Elementary Boron Reactions with Unsaturated Hydrocarbons

National Research Council Canada - National Science Library

Kaiser, Ralf I

2006-01-01

...). It should be recalled that the AFOSR Grant FA9550-05-1-0124 under which the experiments have been conducted was intended as a starter grant to get the experimental setup complete, the boron source...

Nanodiamonds for device applications: An investigation of the properties of boron-doped detonation nanodiamonds.

Science.gov (United States)

Afandi, Abdulkareem; Howkins, Ashley; Boyd, Ian W; Jackman, Richard B

2018-02-19

The inclusion of boron within nanodiamonds to create semiconducting properties would create a new class of applications in the field of nanodiamond electronics. Theoretical studies have differed in their conclusions as to whether nm-scale NDs would support a stable substitutional boron state, or whether such a state would be unstable, with boron instead aggregating or attaching to edge structures. In the present study detonation-derived NDs with purposefully added boron during the detonation process have been studied with a wide range of experimental techniques. The DNDs are of ~4 nm in size, and have been studied with CL, PL, Raman and IR spectroscopies, AFM and HR-TEM and electrically measured with impedance spectroscopy; it is apparent that the B-DNDs studied here do indeed support substitutional boron species and hence will be acting as semiconducting diamond nanoparticles. Evidence for moderate doping levels in some particles (~10 17 B cm -3 ), is found alongside the observation that some particles are heavily doped (~10 20 B cm -3 ) and likely to be quasi-metallic in character. The current study has therefore shown that substitutional boron doping in nm NDs is in fact possible, opening-up the path to a whole host of new applications for this interesting class of nano-particles.

Boron neutron capture therapy (BNCT) inhibits tumor development from precancerous tissue: An experimental study that supports a potential new application of BNCT

International Nuclear Information System (INIS)

Monti Hughes, A.; Heber, E.M.; Pozzi, E.; Nigg, D.W.; Calzetta, O.; Blaumann, H.; Longhino, J.; Nievas, S.I.; Aromando, R.F.; Itoiz, M.E.; Trivillin, V.A.; Schwint, A.E.

2009-01-01

We previously demonstrated the efficacy of boron neutron capture therapy (BNCT) mediated by boronophenylalanine (BPA), GB-10 (Na 2 10 B 10 H 10 ) and (GB-10+BPA) to control tumors, with no normal tissue radiotoxicity, in the hamster cheek pouch oral cancer model. Herein we developed a novel experimental model of field-cancerization and precancerous lesions (globally termed herein precancerous tissue) in the hamster cheek pouch to explore the long-term potential inhibitory effect of the same BNCT protocols on the development of second primary tumors from precancerous tissue. Clinically, second primary tumor recurrences occur in field-cancerized tissue, causing therapeutic failure. We performed boron biodistribution studies followed by in vivo BNCT studies, with 8 months follow-up. All 3 BNCT protocols induced a statistically significant reduction in tumor development from precancerous tissue, reaching a maximum inhibition of 77-100%. The inhibitory effect of BPA-BNCT and (GB-10+BPA)-BNCT persisted at 51% at the end of follow-up (8 months), whereas for GB-10-BNCT it faded after 2 months. Likewise, beam-only elicited a significant but transient reduction in tumor development. No normal tissue radiotoxicity was observed. At 8 months post-treatment with BPA-BNCT or (GB-10+BPA)-BNCT, the precancerous pouches that did not develop tumors had regained the macroscopic and histological appearance of normal (non-cancerized) pouches. A potential new clinical application of BNCT would lie in its capacity to inhibit local regional recurrences.

Boron neutron capture therapy (BNCT) inhibits tumor development from precancerous tissue: An experimental study that supports a potential new application of BNCT

Energy Technology Data Exchange (ETDEWEB)

Monti Hughes, A.; Heber, E.M. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Pozzi, E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Research and Production Reactors, Ezeiza Atomic Center, CNEA, Buenos Aires (Argentina); Nigg, D.W. [Idaho National Laboratory, Idaho Falls, Idaho (United States); Calzetta, O.; Blaumann, H.; Longhino, J. [Department of Nuclear Engineering, Bariloche Atomic Center, CNEA, Rio Negro (Argentina); Nievas, S.I. [Department of Chemistry, CNEA, Buenos Aires (Argentina); Aromando, R.F. [Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Itoiz, M.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Trivillin, V.A. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Schwint, A.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina)], E-mail: schwint@cnea.gov.ar

2009-07-15

We previously demonstrated the efficacy of boron neutron capture therapy (BNCT) mediated by boronophenylalanine (BPA), GB-10 (Na{sub 2}{sup 10}B{sub 10}H{sub 10}) and (GB-10+BPA) to control tumors, with no normal tissue radiotoxicity, in the hamster cheek pouch oral cancer model. Herein we developed a novel experimental model of field-cancerization and precancerous lesions (globally termed herein precancerous tissue) in the hamster cheek pouch to explore the long-term potential inhibitory effect of the same BNCT protocols on the development of second primary tumors from precancerous tissue. Clinically, second primary tumor recurrences occur in field-cancerized tissue, causing therapeutic failure. We performed boron biodistribution studies followed by in vivo BNCT studies, with 8 months follow-up. All 3 BNCT protocols induced a statistically significant reduction in tumor development from precancerous tissue, reaching a maximum inhibition of 77-100%. The inhibitory effect of BPA-BNCT and (GB-10+BPA)-BNCT persisted at 51% at the end of follow-up (8 months), whereas for GB-10-BNCT it faded after 2 months. Likewise, beam-only elicited a significant but transient reduction in tumor development. No normal tissue radiotoxicity was observed. At 8 months post-treatment with BPA-BNCT or (GB-10+BPA)-BNCT, the precancerous pouches that did not develop tumors had regained the macroscopic and histological appearance of normal (non-cancerized) pouches. A potential new clinical application of BNCT would lie in its capacity to inhibit local regional recurrences.

Longitudinal schottky spectra of a bunched Ne10+ ion beam at the CSRe

International Nuclear Information System (INIS)

Wen Weiqiang; Ma Xinwen; Zhang Dacheng

2013-01-01

The longitudinal Schottky spectra of a radio-frequency (RF) bunched and electron cooled 22Ne 10+ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring (CSRe), at IMP. For an RF-bunched ion beam, a longitudinal momentum spread of Δp/p=1.6 × 10 -5 has been reached with less than 107 stored ions. The reduction of momentum spread compared with a coasting ion beam was observed from Schottky noise signal of the bunched ion beam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25 th , 50 th and 75 th harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ion beams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ion beams and nuclear physics at the CSRe. (authors)

A new boronic acid fluorescent sensor based on fluorene for monosaccharides at physiological pH.

Science.gov (United States)

Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona; Eslami, Abbas; Emami, Saeed

2015-06-05

Fluorescent boronic acids are very useful fluorescent sensor for detection of biologically important saccharides. Herein we synthesized a new fluorene-based fluorescent boronic acid that shows significant fluorescence changes upon addition of saccharides at physiological pH. Upon addition of fructose, sorbitol, glucose, galactose, ribose, and maltose at different concentration to the solution of 7-(dimethylamino)-9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (7-DMAFBA, 1), significant decreases in fluorescent intensity were observed. It was found that this boronic acid has high affinity (K(a)=3582.88 M(-1)) and selectivity for fructose over glucose at pH=7.4. The sensor 1 showed a linear response toward d-fructose in the concentrations ranging from 2.5×10(-5) to 4×10(-4) mol L(-1) with the detection limit of 1.3×10(-5) mol L(-1). Copyright © 2015 Elsevier B.V. All rights reserved.

Dielectric track detectors and their applications in boron studies

International Nuclear Information System (INIS)

Mysak, F.; Krejci, M.

1982-01-01

Examples are presented of the applications of autoradiography using plastic films in the study of the distribution of boron in metal materials and its translocation owing to diffusion annealing. Alpha radiation is induced in the material by thermal neutrons while the reaction 10 B(n,α) 7 Li is used. Diffusion processes were studied in the transition zone between the base material and the overlay in hard alloy surfacing. The metallographically treated samples were placed on cellulose nitrate films and irradiated in a reactor. Autoradiograms showed that up to an annealing temperature of 800 degC there was no notable diffusion. Only at 900 degC migration occurred of boron from the transition zone to the base material. Also studied was the distribution of boron in soldered joints of nickel heat resisting alloys. The joints were subjected to homogenization annealing and the gradual disintegration was monitored of boride phases in dependence on the temperature and duration of annealing. Inside the joint boron practically disappeared and it finally appeared in the base material outside of the initial interface. (M.D.)

An empirical model for parameters affecting energy consumption in boron removal from boron-containing wastewaters by electrocoagulation.

Science.gov (United States)

Yilmaz, A Erdem; Boncukcuoğlu, Recep; Kocakerim, M Muhtar

2007-06-01

In this study, it was investigated parameters affecting energy consumption in boron removal from boron containing wastewaters prepared synthetically, via electrocoagulation method. The solution pH, initial boron concentration, dose of supporting electrolyte, current density and temperature of solution were selected as experimental parameters affecting energy consumption. The obtained experimental results showed that boron removal efficiency reached up to 99% under optimum conditions, in which solution pH was 8.0, current density 6.0 mA/cm(2), initial boron concentration 100mg/L and solution temperature 293 K. The current density was an important parameter affecting energy consumption too. High current density applied to electrocoagulation cell increased energy consumption. Increasing solution temperature caused to decrease energy consumption that high temperature decreased potential applied under constant current density. That increasing initial boron concentration and dose of supporting electrolyte caused to increase specific conductivity of solution decreased energy consumption. As a result, it was seen that energy consumption for boron removal via electrocoagulation method could be minimized at optimum conditions. An empirical model was predicted by statistically. Experimentally obtained values were fitted with values predicted from empirical model being as following; [formula in text]. Unfortunately, the conditions obtained for optimum boron removal were not the conditions obtained for minimum energy consumption. It was determined that support electrolyte must be used for increase boron removal and decrease electrical energy consumption.

Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

Science.gov (United States)

Edward Raja, Chellaiah; Omine, Kiyoshi

2013-08-01

Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation.

Microbial decontaminations of species by 10 MeV E- Beam

International Nuclear Information System (INIS)

Mehdizadeh Shahi, A.; Fallahnejad, N.

2005-01-01

Spices are used significantly in food industries. These substances contain high microbial contamination that causes the spoilage of the products and it is also hazardous for the health of consumers. Irradiation is one of the most effective methods to decontaminate spices. In this research , the optimum dose of e-beams to reduce microbial contamination of spices is determined. Samples of spices such as: turmeric, black pepper, garlic powder, onion powder, oregano and spice, were packaged in 10 grams, and they were irradiated at the dose of 0-10 kGy by 10 MeV e-beams. After irradiation, the total microbial counts were determined by the pour plating method. The bacterial contamination of different spices was between 10 5 to 4.7 x 10 7 cfu/gr and the molds count was between 1.8x10 2 to 7.2 x 10 3 cfu/gr. The survival curve of the bacteria was drawn in terms of bio burden versus the radiation dose rates. By determining the D 10 value, the minimum dose for reducing the spices microbial contamination up to the optimum limit, were identified

Boron neutron capture therapy (BNCT) for glioblastoma multiforme (GBM), using the epithermal neutron beam at the Brookhaven National Laboratory

International Nuclear Information System (INIS)

Chadha, Manjeet; Capala, Jacek; Coderre, Jeffrey A.; Elowitz, Eric H.; Joel, Darrel D.; Hungyuan, B. Liu; Slatkin, Daniel N.; Chanana, Arjun D.

1996-01-01

Objective: BNCT is a binary treatment modality based on the nuclear reactions that occur when boron ( 10 B) is exposed to thermal neutrons. Preclinical studies have demonstrated the therapeutic efficacy of p-boronophenylalanine (BPA)-based BNCT. The objective of the Phase I/II trial was to evaluate BPA-fructose (BPA-F) as a boron delivery agent for GBM and to study the feasibility and safety of a single-fraction of BNCT. Materials and Methods: The trial design required i) a BPA-F biodistribution study performed at the time of craniotomy; and ii) BNCT within 4 weeks of the craniotomy. From September 94 to July 95, 10 patients with biopsy proven GBM were treated. All but 1 patient underwent a biodistribution study receiving IV BPA-F at the time of craniotomy. Multiple tissue samples and concurrent blood and urine samples were collected for evaluation of the boron concentration and clearance kinetics. For BNCT all patients received 250 mg/kgm of BPA-F (IV infusion over 2 hrs) followed by neutron irradiation. The blood 10 B concentration during irradiation was used to calculate the time of neutron exposure. The 3D treatment planning was done using the BNCT treatment planning software developed at the Idaho National Engineering Laboratory. The BNCT dose is expressed as the sum of the physical dose components corrected for both the RBE and the 10 B localization factor with the unit Gy-Eq. The photon-equivalent dose, where the thermal neutron fluence reaches a maximum, is the peak-dose equivalent. A single-fraction of BNCT was delivered prescribing 10.5 Gy-Eq (9 patients) and 13.8 Gy-Eq (1 patient) as the peak dose-equivalent to the normal brain. The peak dose rate was kept below 27 cGy-Eq/min. Results: Biodistribution data: The maximum blood 10 B concentration was observed at the end of the infusion and scaled as a linear function of the administered dose. The 10 B concentration in the scalp and in the GBM tissue was higher than in blood by 1.5 x and at least 3.5 x

Improved ductility of Ni3Si by microalloying with boron or carbon

International Nuclear Information System (INIS)

Taub, A.I.; Briant, C.L.

1989-01-01

The effects of boron and carbon additions on the tendency for intergranular fracture in trinickel silicide intermetallics are reported. Melt spinning of Ni 77 Si 23 alloyed with 0.1 at. pct boron results in full bend ductility and complete transgranular fracture compared with brittle intergranular fracture for the unmodified compound. Alloying with 0.1 at. pct carbon also produced full bend ductility but a mixed mode failure (30 pct transgranular). For both carbon and boron additions, reducing the Ni concentration of the base compound results in a greater percentage of intergranular fracture. For Ni 77 Si 23 , the solubility limit is between 0.1 and 0.2 t. pct boron. For compounds with silicon concentrations of 23.5 and 24.0 at. pct, the solubility limit is less than 0.1 at. pct boron. Boron additions above the solubility limit result in Ni 3 B precipitates which degrade the bend ductility and increase the percentage of intergranular fracture. Alloying with carbon above the solubility limit ( 77 Si 23 , increasing the carbon concentration from 0.1 to 1.0 at. pct resulted in no change in the ductility. Auger examination of the grain boundary composition showed strong segregation of both boron and carbon. Enrichment in silicon concentration was also observed

A Simulation Study for Radiation Treatment Planning Based on the Atomic Physics of the Proton-Boron Fusion Reaction

Energy Technology Data Exchange (ETDEWEB)

Kim, Sunmi; Yoon, Do-Kun; Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Kyeong-Hyeon; Jang, Hong-Seok; Suh, Tae Suk [the Catholic University of Korea, Seoul (Korea, Republic of)

2017-03-15

The purpose of this research is to demonstrate, based on a Monte Carlo simulation code, the procedure of radiation treatment planning for proton-boron fusion therapy (PBFT). A discrete proton beam (60 - 120 MeV) relevant to the Bragg peak was simulated using a Monte Carlo particle extended (MCNPX, Ver. 2.6.0, National Laboratory, Los Alamos NM, USA) simulation code. After computed tomography (CT) scanning of a virtual water phantom including air cavities, the acquired CT images were converted using the simulation source code. We set the boron uptake regions (BURs) in the simulated water phantom to achieve the proton-boron fusion reaction. Proton sources irradiated the BUR, in the phantom. The acquired dose maps were overlapped with the original CT image of the phantom to analyze the dose volume histogram (DVH). We successfully confirmed amplifications of the proton doses (average: 130%) at the target regions. From the DVH result for each simulation, we acquired a relatively accurate dose map for the treatment. A simulation was conducted to characterize the dose distribution and verify the feasibility of proton boron fusion therapy (PBFT). We observed a variation in proton range and developed a tumor targeting technique for treatment that was more accurate and powerful than both conventional proton therapy and boron-neutron capture therapy.

Pulverization of boron element and proportions of boron carbide in boron; Broyage de bore element et dosage de carbure de bore dans le bore

Energy Technology Data Exchange (ETDEWEB)

Lang, F M; Finck, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

It is possible to reduce boron element into fine powder by means of a mortar and pestle made of sintered boron carbide, the ratio of boron carbide introduced being less than one per cent. Boron element at our disposal is made of sharp edged, dark brown, little grains of average size greater than 5 {mu}. Grain sizes smaller than 1{mu} are required for applying thin layers of such boron. (author) [French] Il est possible de pulveriser finement du bore element au moyen de mortier et pilon en carbure de bore fritte, le taux de carbure de bore introduit etant inferieur a 1 pour cent. Le bore element dont nous disposons est constitue de petits grains brun fonce, a aretes vives, de dimension moyenne superieure a 5 {mu}. L'application de ce bore en couches minces demande des grains de dimensions inferieures a 1 {mu}. (aute0008.

Boron uptake measurements in a rat model for Boron Neutron Capture Therapy of lung tumours

Energy Technology Data Exchange (ETDEWEB)

Bortolussi, S., E-mail: silva.bortolussi@pv.infn.i [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Bakeine, J.G. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Ballarini, F. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Gadan, M.A. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Protti, N.; Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Clerici, A.; Ferrari, C.; Cansolino, L.; Zonta, C.; Zonta, A. [Department of Surgery, University of Pavia, via Ferrata 27100 Pavia (Italy); Nano, R. [Department of Animal Biology, University of Pavia, via Ferrata 27100 Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy)

2011-02-15

Lung carcinoma is the leading cause of cancer mortality in the Western countries. Despite the introduction over the last few years of new therapeutic agents, survival from lung cancer has shown no discernible improvement in the last 20 years. For these reasons any efforts to find and validate new effective therapeutic procedures for lung cancer are very timely. The selective boron uptake in the tumour with respect to healthy tissues makes Boron Neutron Capture Therapy a potentially advantageous option in the treatment of tumours that affect whole vital organs, and that are surgically inoperable. To study the possibility of applying BNCT to the treatment of diffuse pulmonary tumours, an animal model for boron uptake measurements in lung metastases was developed. Both healthy and tumour-bearing rats were infused with Boronophenylalanine (BPA) and sacrificed at different time intervals after drug administration. The lungs were extracted, and prepared for boron analysis by neutron autoradiography and {alpha}-spectroscopy. The boron concentrations in tumour and normal lung were plotted as a function of the time elapsed after BPA administration. The concentration in tumour is almost constant within the error bars for all the time intervals of the experiment (1-8 h), while the curve in normal lung decreases after 4 h from BPA infusion. At 4 h, the ratio of boron concentration in tumour to boron concentration in healthy lung is higher than 3, and it stays above this level up to 8 h. Also the images of boron distribution in the samples, obtained by neutron autoradiography, show a selective absorption in the metastases.

Study of the beam-cavity interaction in the CERN PS 10 MHz cavities and investigation of hardware solutions to reduce beam loading

CERN Document Server

AUTHOR|(CDS)2086984; Palumbo, Luigi

In the Proton Synchrotron (PS), where the LHC protons longitudinal structure (bunch spacing) is determined as the result of a sophisticated series of Radio Frequency (RF) gymnastics, collective effects were identified as a major limitation to the achievable beam current delivered to the LHC. Dedicated machine development studies pointed out the RF cavities to be one of the major source of instability in the PS. In particular, the 10 MHz RF system, responsible for beam acceleration, was identified as the most probable impedance source in the machine. The cavity impedance limits the circulating intensity in the accelerator since the beam-induced voltage could trigger longitudinal instabilities causing beam losses. For this reason the cavity impedance seen by the beam must be kept as low as possible. In the framework of the LHC Injector Upgrade (LIU) project, the present PS 10 MHz RF system requires an upgrade, in order to reach higher beam intensities and to reduce beam loading. This thesis focuses on the impro...

High-power liquid-lithium target prototype for accelerator-based boron neutron capture therapy.

Science.gov (United States)

Halfon, S; Paul, M; Arenshtam, A; Berkovits, D; Bisyakoev, M; Eliyahu, I; Feinberg, G; Hazenshprung, N; Kijel, D; Nagler, A; Silverman, I

2011-12-01

A prototype of a compact Liquid-Lithium Target (LiLiT), which will possibly constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals, was built. The LiLiT setup is presently being commissioned at Soreq Nuclear Research Center (SNRC). The liquid-lithium target will produce neutrons through the (7)Li(p,n)(7)Be reaction and it will overcome the major problem of removing the thermal power generated using a high-intensity proton beam (>10 kW), necessary for sufficient neutron flux. In off-line circulation tests, the liquid-lithium loop generated a stable lithium jet at high velocity, on a concave supporting wall; the concept will first be tested using a high-power electron beam impinging on the lithium jet. High intensity proton beam irradiation (1.91-2.5 MeV, 2-4 mA) will take place at Soreq Applied Research Accelerator Facility (SARAF) superconducting linear accelerator currently in construction at SNRC. Radiological risks due to the (7)Be produced in the reaction were studied and will be handled through a proper design, including a cold trap and appropriate shielding. A moderator/reflector assembly is planned according to a Monte Carlo simulation, to create a neutron spectrum and intensity maximally effective to the treatment and to reduce prompt gamma radiation dose risks. Copyright © 2011 Elsevier Ltd. All rights reserved.

A system to deposit boron films (boronization) in the DIII-D tokamak

International Nuclear Information System (INIS)

Hodapp, T.R.; Jackson, G.L.; Phillips, J.; Holtrop, K.L.; Petersen, P.I.; Winter, J.

1991-09-01

A system has been added to the D3-D tokamak to coat its plasma facing surfaces with a film of boron using diborane gas. The system includes special health and safety equipment for handling the diborane gas which is toxic and inflammable. The purpose of the boron film is to reduce the levels of impurity atoms in the D3-D plasmas. Experiments following the application of the boron film in D3-D have led to significant reductions in plasma impurity levels and the observation of a new, very high confinement regime. 9 refs., 1 fig

A study of the distribution and uptake of boron in mango fruits using neutron-capture-radiography

International Nuclear Information System (INIS)

Loria, G.; Jimenez, R.; Gallardo, M.; Martini, F.; Thellier, M.

1992-01-01

The method of neutron-capture-radiography (NCR) was used to study the distribution of boron in mango fruit. There was a regular decrease of the concentration of natural boron from the skin (83.9 ppm, dry weight) to the interior of the fruit (2.4 ppm, dry weight, 5.6 mm deep in the fruit). When drops of a solution of ( 10 B)BO 3 H 3 were placed on the fruit surface, boron accumulated in restricted zones, within the fruit skin, which apparently corresponded to skin secretory-glands. The apparent coefficient of diffusion of boric acid from these zones of high boron accumulation to the interior of the fruit was of the order of 1.6 x 10 -12 m 2 s -1

Boron neutron capture therapy. Synthesis of boronated amines- and DNA intercalating agents for potential use in cancer therapy

International Nuclear Information System (INIS)

Ghaneolhosseini, H.

1998-01-01

Boron Neutron Capture Therapy is a binary cancer treatment modality, involving the delivery of a suitable boron compound to tumour cells followed by irradiation of the tumour by thermal neutrons. Boronated agents can selectively be delivered to tumour cells either directly with tumour-specific boron compounds, or by use of targeting strategies. However, the efficacy of this method would increase if the boron agents are localised in the cell nucleus rather than in the cell cytoplasm when neutron irradiation takes place. With these considerations in mind, some boronated DNA intercalating/interacting agents such as phenanthridine- acridine- spermidine- and naphthalimide derivatives were synthesised. Aminoalkyl-o-carboranes were synthesised in order to be used both for coupling to macromolecules and also for halogenation of their corresponding nido-derivatives. The amino groups were introduced using the Gabriel reagent N, N-dibenzyl iminodicarboxylate to provide 1-(aminomethyl)- and 1-(2-aminoethyl)-o-carboranes. The first attempt to achieve the possibility to accumulate a higher concentration of boron atoms in the cell nucleus was to synthesize carboranyl phenanthridinium analogues by reacting a p- or o-carboranyl moiety with phenanthridine, a chromophore with a planar aromatic ring system as DNA intercalator. Boronated acridine-spermidine, boronated diacridine, and boronated dispermidine were obtained in order to increase water solubility to avoid the interaction of these agents with non-DNA sides of the cell, especially membranes; and to enhance the feasibility of a higher DNA-binding constant and also decrease the DNA-drug dissociation rate. Finally, the synthesis of a boronated naphthalimide derivative was carried out by nucleophilic reaction of a primary aminoalkyl-p-carborane with naphthalic anhydride. Biological evaluations on DNA-binding, toxicity, and cellular binding with carboranyl phenanthridinium analogues, boronated acridine- and spermidine are described

Modeling of the hot flow behavior of advanced ultra-high strength steels (A-UHSS) microalloyed with boron

International Nuclear Information System (INIS)

Mejía, I.; Altamirano, G.; Bedolla-Jacuinde, A.; Cabrera, J.M.

2014-01-01

In this research work, modeling of the hot flow behavior was carried out in a low carbon advanced ultra-high strength steels (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm). For this purpose, experimental stress–strain data of uniaxial hot-compression tests over a wide range of temperatures (1223, 1273, 1323 and 1373 K (950, 1000, 1050 and 1100 °C)) and strain rates (10 −3 , 10 −2 and 10 −1 s −1 ) were used. The stress–strain relationships as a function of temperature and strain rate were successfully described on the basis of the approach proposed by Estrin, Mecking, and Bergström, together with the classical Avrami equation and the conventional hyperbolic sine function. The analysis of the modeling parameters of the hot flow curves shows that boron additions to A-UHSS play a major role in softening mechanisms rather than on hardening. The peak stress (σ p ) and steady-state stress (σ ss ) values show a decreasing trend with increasing boron content, which indicates that boron additions promote a solid solution softening effect additional to that produced by DRX. The time for 50% recrystallization (t 50% ) tends to increase with boron additions, revealing that boron additions cause a delay of the DRX kinetics during hot deformation. Similarly, the presence of boron in the steel decreases the apparent activation energy for recrystallization (Q t ), indicating that boron additions accelerate the onset of DRX. The constitutive equations developed in this way provided an excellent description of the experimental hot flow curves

Therapeutic efficacy of boron neutron capture therapy mediated by boron-rich liposomes for oral cancer in the hamster cheek pouch model

Energy Technology Data Exchange (ETDEWEB)

Heber, Elisa M. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Hawthorne, M. Frederick [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Kueffer, Peter J. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Garabalino, Marcela A. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Thorp, Silvia I. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Pozzi, Emiliano C. C. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Hughes, Andrea Monti [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Maitz, Charles A. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Jalisatgi, Satish S. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Nigg, David W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Curotto, Paula [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Trivillin, Verónica A. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Schwint, Amanda E. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina)

2014-11-11

Unilamellar liposomes formulated with an equimolar mixture of cholesterol and 1,2-distearoyl-sn-glycero-3-phosphocholine, incorporating K[nido-7-CH₃(CH₂)15-7,8-C₂B₉H₁₁] in the lipid bilayer, and encapsulating Na₃[1-(2’-B₁₀-H₉)-2-NH₃B₁₀H₈] were prepared by probe sonication and investigated in vivo. Microwave assisted digestion followed by inductively coupled plasma-optical emission spectroscopy was utilized to determine the biodistribution of boron in various tissues following either a single tail vein injection or two identical injections (separated by 24 hours) of the liposomal suspension in BALB/c mice bearing EMT6 mammary adenocarcinomas in their right flank. Double-injection protocols resulted in a boron content in the tumor exceeding 50 µg of boron per gram of tissue for 48 to 72 hours subsequent to the initial injection while tumor:blood boron ratios were more ideal from 54 hours (1.9:1) to 96 hours (5.7:1) subsequent to the initial injection. Tumor bearing mice were given a double-injection of liposomes containing the ¹⁰B-enriched analogs of the aforementioned agents and subjected to a 30 minute irradiation by thermal neutrons with a flux of 8.8 x 10⁸ (±7%) neutrons/cm² s integrated over the energy range of 0.0 – 0.414 eV. Significant tumor response for a single BNCT treatment was demonstrated by growth curves versus a control group. Vastly diminished tumor growth was witnessed at 14 days (186% increase versus 1551% in controls) in mice that were given a second injection/radiation treatment 7 days after the first. Mice given a one hour neutron irradiation following the double-injection of liposomes had a similar response (169% increase at 14 days) suggesting that neutron fluence is the limiting factor towards BNCT efficacy in this study.

Differentiation in boron distribution in adult male and female rats' normal brain: A BNCT approach

Energy Technology Data Exchange (ETDEWEB)

Goodarzi, Samereh, E-mail: samere.g@gmail.com [Department of Nuclear Engineering, Science and Research Branch, Islamic Azad University, PO Box 19395-1943, Tehran (Iran, Islamic Republic of); Pazirandeh, Ali, E-mail: paziran@yahoo.com [Department of Nuclear Engineering, Science and Research Branch, Islamic Azad University, PO Box 19395-1943, Tehran (Iran, Islamic Republic of); Jameie, Seyed Behnamedin, E-mail: behnamjameie@tums.ac.ir [Basic Science Department, Faculty of Allied Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Anatomy, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Baghban Khojasteh, Nasrin, E-mail: khojasteh_n@yahoo.com [Department of Nuclear Engineering, Science and Research Branch, Islamic Azad University, PO Box 19395-1943, Tehran (Iran, Islamic Republic of)

2012-06-15

Boron distribution in adult male and female rats' normal brain after boron carrier injection (0.005 g Boric Acid+0.005 g Borax+10 ml distilled water, pH: 7.4) was studied in this research. Coronal sections of control and trial animal tissue samples were irradiated with thermal neutrons. Using alpha autoradiography, significant differences in boron concentration were seen in forebrain, midbrain and hindbrain sections of male and female animal groups with the highest value, four hours after boron compound injection. - Highlights: Black-Right-Pointing-Pointer Boron distribution in male and female rats' normal brain was studied in this research. Black-Right-Pointing-Pointer Coronal sections of animal tissue samples were irradiated with thermal neutrons. Black-Right-Pointing-Pointer Alpha and Lithium tracks were counted using alpha autoradiography. Black-Right-Pointing-Pointer Different boron concentration was seen in brain sections of male and female rats. Black-Right-Pointing-Pointer The highest boron concentration was seen in 4 h after boron compound injection.

Evaluation of JRR-4 neutron beam using tumor cells

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Kishi, Toshiaki; Horiguchi, Yoji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan)

2001-03-01

For preparation of irradiation plan of boron-neutron capture therapy (BNCT), not only the physical dose is important, but also weighted factors or RBE are also necessary on the evaluation of the effect on the organism. Physical dose calculated by dose evaluation system (JCDS : JAERI Computational Dosimetry System) must appropriately carry out the weighting by various cells like tumor, central nerve, glia, and the vascular in proportion to JRR-4 each irradiation mode. In-vitro biological experiment which used 9L gliosarcoma and C6 glioma in the head water phantom was carried out in order to evaluate these effect. Neutron beam characteristics of JRR-4 were also evaluated from the functions of survival fraction of these cells. As a result of the evaluation, it became clear that the dose evaluation calculated from physical dose of the boron and nitrogen carried out in traditional BNCT of Japan using thermal neutron is applicable for thermal and epi-thermal mixed neutron beam. (author)

Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride-hydroxy apatite in rat femurs.

Science.gov (United States)

Atila, Alptug; Halici, Zekai; Cadirci, Elif; Karakus, Emre; Palabiyik, Saziye Sezin; Ay, Nuran; Bakan, Feray; Yilmaz, Sahin

2016-01-01

Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN-HA composites in rat femurs. All rats were (n=126) divided into five experimental groups (n=24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100 HA (Group2), femoral defect + %2.5 hBN + %97.5 HA (Group3), femoral defect + %5 hBN + %95 HA (Group4), femoral defect + %10 hBN + %90 HA (Group5), femoral defect + %100 hBN (Group6). The femoral defect was created in the distal femur (3mm drill-bit). Each implant group was divided into four different groups (n=24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN-HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN-HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. Copyright © 2015 Elsevier B.V. All rights reserved.

Product conveying system for 10 MeV electron beam accelerator for electron beam centre, Kharghar, Navi Mumbai

International Nuclear Information System (INIS)

Bandi, L.N.; Lavale, D.S.; Sarma, K.S.S.; Khader, S.A.; Assadullah, M.; Sabharwal, S.

2003-01-01

In industrial radiation processing applications using accelerators, product conveying system plays a vital role in exposing the product to high energy electron beam for imparting specified dose to the product and delivering required through puts. The speed of the conveyor corresponds to a definite time of exposure of the product in the radiation zone. Design of suitable conveyor system for a variety of products with differing dose requirements call for a conveyor with wide speed range. This paper discusses the design features of a suitable under beam conveyor system for 10 MeV, 10 kW accelerator for processing a range of products including medical and food products

Removal of boron (B) from waste liquors.

Science.gov (United States)

Jiang, J Q; Xu, Y; Simon, J; Quill, K; Shettle, K

2006-01-01

This paper explores the use of electrocoagulation to remove boron from waste effluent in comparison with alum coagulation. In treating model test wastes, greater boron removals were achieved with electrocoagulation at low doses than conventional alum coagulation when reaction was undertaken for the same conditions (pH 8.5, and initial boron concentration was 500 mg/L). Al electrocoagulation can achieve good boron removal performance (68.3%) at a dose of 2.1 (as molar ratio of Al:B, and for current density of 62.1 A/m2), while alum coagulation can only achieve the maximum boron removal of 56% at a dose of 2.4. Also, Al electrocoagulation can remove 15-20% more boron than alum coagulation for the same dose compared in the treatment of both model test wastes and industry effluent. The estimation of running costs shows that to achieve 75% boron removal from industry waste effluent, i.e. removing 150 g of boron from 1 m3 of effluent, electrocoagulation was 6.2 times cheaper than alum coagulation. The economic advantage of electrocoagulation in the treatment of boron-containing waste effluent is thus significant.

Determination of very small contents of boron by pH difference measurement

International Nuclear Information System (INIS)

Boehm, H.; Kirmse, E.M.; Schilbach, U.

1983-01-01

For the determination of boron as a trace element for food of plants in a very complicated salt matrix an analytical proceeding was developed, which allows to determine the content of boron without separation. The principle of analysis is based on the esterification of boric acid with a multivalent alcohol, which leeds to a monovalent strong complex acid. The change of the pH value of the analysing solution is measured. From the initial pH number, the end pH number, the volume of the analysing solution and the ionic product of water corresponding with the operating temperature the quantity of boric acid of boron that is equivalent the produced quantity of H + -ions is calculated by means of a linear program. The standard deviation of analytical proceeding amounts to 13.9 ng B. For the determination of the contents of boron of an unknown sample, five to ten separate measurements are carried out. For solutions, which are about 1x10 -6 M of boric acid, there are necessary 10 ml of sample for each separate measurement. The confidence interval of analytical results is found to be between +- 0.5 and +- 15.5% (P=0.99). For the determination of the content of boron in plant materials about 50-100 mg of dry weight are necessary. (Author)

The expert system OPTRAN (Ver 1.0) and its application to beam transportation line design

International Nuclear Information System (INIS)

Xiao Meiqin; Lu Hongyou; Fan Mingwu

1994-01-01

The expert system OPTRAN (Ver 1.0) used for beam transportation line design is introduced. The knowledge storage and reasoning principle, of which the intelligence part of OPTRAN are composed, have been described in detail. By using OPTRAN (Ver 1.0), the design of a beam transportation line for extracted ion beam of Cyclone 30 was completed

Electronic response of a photodiode coupled to a boron thin film

Energy Technology Data Exchange (ETDEWEB)

Costa, Priscila; Costa, Fabio E.; Raele, Marcus P.; Zahn, Guilherme S.; Geraldo, Bianca; Vieira Junior, Nilson D.; Samad, Ricardo E.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

A portable thermal neutron detector is proposed in this work using a silicon photodiode coupled to a boron thin film. The aim of this work was to verify the effect in the electronic response of this specific photodiode due to boron deposition, since the direct deposition of boron in the semiconductor surface could affect its electrical properties specifically the p-type layer that affects directly the depletion region of the semiconductor reducing the neutron detector efficiency count. Three boron depositions with different thickness were performed in the photodiode (S3590-09) surface by pulsed laser deposition and the photodiode was characterized, before and after the deposition process, using a radioactive americium source. Energy spectra were used to verify the electronic response of the photodiode, due to the fact that it is possible to relate it to the photopeak pulse height and resolution. Spectra from the photodiode without and with boron film deposition were compared and a standard photodiode (S3590-04) that had the electronic signal conserved was used as reference to the pulse height for electronics adjustments. The photopeak energy resolution for the photodiode without boron layer was 10.26%. For the photodiode with boron deposition at different thicknesses, the resolution was: 7.64 % (0.14 μm), 7.30 % (0.44 μm) and 6.80 % (0.63 μm). From these results it is possible to evaluate that there was not any degradation in the silicon photodiode. (author)

SPES-BNCT Project Beam Shaping Assembly. State of the Art

International Nuclear Information System (INIS)

Ceballos Sanchez, Cesar

2007-01-01

The SPES-BNCT project will exploit the intense proton beam provided by the RFQ (30mA, 5MeV), currently under construction at LNL, to yield a neutron source using the 9 Be(p,xn) nuclear reaction. The goal is to setup an accelerator-driven, thermal neutron beam facility, aimed at the Boron Neutron Capture experimental treatment of extended shallow skin melanoma. The neutron energy spectrum is shifted with a beam shaping assembly (BSA) surrounding the target. This device is fully designed with the Monte Carlo simulation code MCNPX, with the purpose of maximizing the thermal neutron component of the beam and focusing it on the irradiation area. (Author)

Boron Neutron Capture Therapy (BNCT) in an experimental model of lung metastases in BDIX rats

International Nuclear Information System (INIS)

Trivillin, V.A.; Garabalino, M.A.; Colombo, L.L.

2013-01-01

Boron Neutron Capture Therapy (BNCT) in an experimental model of lung metastases in BDIX rats Introduction: Boron Neutron Capture Therapy (BNCT) is based on selective tumor uptake of boron compounds, followed by neutron irradiation. BNCT was proposed for the treatment of unresectable, diffuse lung metastases. The aim of the present study was to perform BNCT studies in an experimental model of lung metastases. Materials and Methods: 3 x 106/0.5 ml colon carcinoma cells (DHD/K12/TRb) were injected iv in syngeneic BDIX rats. Three weeks post-inoculation, rats with diffuse lung metastases were used for in vivo BNCT studies in the RA-3 Nuclear Reactor. Based on previous biodistribution studies and computational dosimetry with Monte Carlo simulation, 2 doses were prescribed, i.e. 4 Gy and 8 Gy minimum absorbed dose to tumor. The animals were assigned to 5 experimental groups (n= 4 to 8) at each dose level: T0 (euthanized pre-treatment), BPA-BNCT, Comb-BNCT (BPA+GB-10), Beam only (background dose) and Sham (same manipulation, no treatment). Boron concentration was measured in a blood sample taken pre-irradiation to verify that the value was in the range established in previous biodistribution studies. The animals were followed clinically for 2 weeks after neutron irradiation and then euthanized to assess the response of tumor and normal lung, macroscopically and histologically. To date we have evaluated the end-point weight of lung (normal lung + metastases) and % lung weight/body weight as an indicator of tumor growth. Results: The statistical analysis (ANOVA) of % lung weight/body weight showed statistically significant differences (p<0.05) between groups T0 (0.79 ± 0.38) and Sham (1.87 ± 0.91). No statistically significant differences were observed between the Beam only groups (at both dose levels) and Sham. Similar and statistically significant tumor control was induced in the groups BPA-BNCT Low dose (LD) (0.56 ± 0.11), BPA-BNCT High dose (HD) (0.80 ± 0.16), Comb

Laser-time resolved fluorimetric determination of trace of boron in U3O8

International Nuclear Information System (INIS)

Xu Yongyuan; Wang Yulong; Wang Qin

1988-01-01

In this work, a laser-time resolved fluorimetric determinatin of trace of boron in U 3 O 8 had been developed. The boron complex with dibenzoyl methane (DBM) in a suitable medium is excited by a small nitrogen laser and emits the delay fluorescence with lifetime of 2 ms which is much longer than that of the fluorescence of uranium. Since the fluorescence of uranium doesn't interfere with determination of boron in the time resolved fluorimetric method boron need not be separated from uranium in advance. Thus the determination is very rapid and simple. The limit of determination is 0.02 ngB/ml. When 10 mgU is taken, 0.01 ppm of boron in uranium can be determined. Several samples of U 3 O 8 with boron content from 0.04 to 0.5 ppm have been determined by using this method. The results of determination have been accordant with other methods

Microstructure of a high boron 9-12% chromium steel

Energy Technology Data Exchange (ETDEWEB)

Andren, H.O. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Applied Physics

2008-07-01

Additions of small amounts of boron (10-100 ppm) to 9-12% chromium steels are often made since they have been found to be beneficial for the creep strength up to and above 600 C. The effect of boron is to restrict the coarsening of M{sub 23}C{sub 6} precipitates during service. It was found that increasing the boron content from 9 to 40 ppm gave a decrease in coarsening constant at 600 C by a factor of 2. The present understanding of boron solution, non-equilibrium grain boundary segregation, incorporation into M{sub 23}C{sub 6}, and diffusion is reviewed in the paper. A very high boron addition (300 ppm) was made in the trial TAF steel already in the 1950'ies. The microstructure of a similar trial steel, FT3B, has been studied detail. In this steel large Mo, Cr, Fe and V containing metal borides are formed rather than the expected BN, with the crystal structure M{sub 2}B{sub 2}. Nitrogen is therefore still available for the formation of VN. Due to tempering at a low temperature (690 C) to a high strength (830 MPa), this steel contained a dense distribution of very small VN precipitates, 5-15 nm in size. A similar VN distribution is probably the cause of the still unsurpassed creep strength of the TAF steel. (orig.)

SHB1/HY1 Alleviates Excess Boron Stress by Increasing BOR4 Expression Level and Maintaining Boron Homeostasis in Arabidopsis Roots

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Qiang Lv

2017-05-01

Full Text Available Boron is an essential mineral nutrient for higher plant growth and development. However, excessive amounts of boron can be toxic. Here, we report on the characterization of an Arabidopsis mutant, shb1 (sensitive to high-level of boron 1, which exhibits hypersensitivity to excessive boron in roots. Positional cloning demonstrated that the shb1 mutant bears a point mutation in a gene encoding a heme oxygenase 1 (HO1 corresponding to the HY1 gene involved in photomorphogenesis. The transcription level of the SHB1/HY1 gene in roots is up-regulated under excessive boron stimulation. Either overexpressing SHB1/HY1 or applying the HO1 inducer hematin reduces boron accumulation in roots and confers high boron tolerance. Furthermore, carbon monoxide and bilirubin, catalytic products of HO1, partially rescue the boron toxicity-induced inhibition of primary root growth in shb1. Additionally, the mRNA level of BOR4, a boron efflux transporter, is reduced in shb1 roots with high levels of boron supplementation, and hematin cannot relieve the boron toxicity-induced root inhibition in bor4 mutants. Taken together, our study reveals that HO1 acts via its catalytic by-products to promote tolerance of excessive boron by up-regulating the transcription of the BOR4 gene and therefore promoting the exclusion of excessive boron in root cells.

A neutron dynamic therapy with a boron tracedrug UTX-51 using a compact neutron generator.

Science.gov (United States)

Hori, Hitoshi; Tada, Ryu; Uto, Yoshihiro; Nakata, Eiji; Morii, Takashi; Masuda, Kai

2014-08-01

We are developing a neutron dynamic therapy (NDT) with boron tracedrugs for a new mechanical-clearance treatment of pathotoxic misfolded, aggregated, and self-propagating prion-associated disease proteins. We present a compact neutron generator-based NDT using a boron tracedrug UTX-51. Our NDT is based on the weak thermal neutron-bombarded destructive action of UTX-51 on bovine serum albumin (BSA) using the neutron beams produced from a compact inertial electrostatic confinement fusion (IECF) neutron generator. BSA as an NDT molecular target was subjected to thermal neutron irradiation for eight hours using a compact neutron generator. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern showed no protein band when 2 nmoles of BSA were irradiated with more than 100 nmoles of UTX-51, while BSA was not affected when irradiated without UTX-51. For the first time, we have succeeded in the molecular destruction of a prion-disease model protein, BSA, by NDT with a boron tracedrug, UTX-51, using a compact neutron generator. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Boron rates for triticale and wheat crops

Directory of Open Access Journals (Sweden)

Corrêa Juliano Corulli

2005-01-01

Full Text Available No reports are registered on responses to boron fertilization nutrient deficiency and toxicity in triticale crops. The aim of this study was to evaluate triticale response to different rates of boron in comparison to wheat in an hapludox with initial boron level at 0.08 mg dm-3 4 4 factorial design trial completely randomized blocks design (n = 4. Boron rates were 0; 0.62; 1.24 and 1.86 mg dm-3; triticale cultivars were IAC 3, BR 4 and BR 53 and IAPAR 38 wheat crop was used for comparison. The wheat (IAPAR 38 crop presented the highest boron absorption level of all. Among triticale cultivars, the most responsive was IAC 53, presenting similar characteristics to wheat, followed by BR 4; these two crops are considered tolerant to higher boron rates in soil. Regarding to BR 53, no absorption effect was observed, and the cultivars was sensitive to boron toxicity. Absorption responses differed for each genotype. That makes it possible to choose and use the best-adapted plants to soils with different boron rates.

An EXAFS spectrometer on beam line 10B at the Photon Factory

International Nuclear Information System (INIS)

Oyanagi, Hiroyuki; Matsushita, Tadashi; Ito, Masahisa; Kuroda, Haruo.

1984-03-01

An EXAFS spectrometer installed on the beam line 10B at the Photon Factory is designed to cover the photon energy between 4 and 30 keV. Utilizing either a channel-cut or two flat silicon crystals as a monochromator, a beam intensity between 10 8 and 10 9 photons/sec is obtained at 9 keV with a resolution of 1 eV. The performance of the spectrometer, such as a signal-to-noise ratio or an energy resolution is demonstrated with examples of K edge absorption spectra of bromine, germanium, gallium arsenide, and zinc selenide. (author)

Amorphous boron nanorod as an anode material for lithium-ion batteries at room temperature.

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Deng, Changjian; Lau, Miu Lun; Barkholtz, Heather M; Xu, Haiping; Parrish, Riley; Xu, Meiyue Olivia; Xu, Tao; Liu, Yuzi; Wang, Hao; Connell, Justin G; Smith, Kassiopeia A; Xiong, Hui

2017-08-03

We report an amorphous boron nanorod anode material for lithium-ion batteries prepared through smelting non-toxic boron oxide in liquid lithium. Boron in theory can provide capacity as high as 3099 mA h g -1 by alloying with Li to form B 4 Li 5 . However, experimental studies of the boron anode have been rarely reported for room temperature lithium-ion batteries. Among the reported studies the electrochemical activity and cycling performance of the bulk crystalline boron anode material are poor at room temperature. In this work, we utilized an amorphous nanostructured one-dimensional (1D) boron material aiming at improving the electrochemical reactivity between boron and lithium ions at room temperature. The amorphous boron nanorod anode exhibited, at room temperature, a reversible capacity of 170 mA h g -1 at a current rate of 10 mA g -1 between 0.01 and 2 V. The anode also demonstrated good rate capability and cycling stability. The lithium storage mechanism was investigated by both sweep voltammetry measurements and galvanostatic intermittent titration techniques (GITTs). The sweep voltammetric analysis suggested that the contributions from lithium ion diffusion into boron and the capacitive process to the overall lithium charge storage are 57% and 43%, respectively. The results from GITT indicated that the discharge capacity at higher potentials (>∼0.2 V vs. Li/Li + ) could be ascribed to a capacitive process and at lower potentials (ions and the amorphous boron nanorod. This work provides new insights into designing nanostructured boron materials for lithium-ion batteries.

Boron neutron capture therapy of intracerebral rat gliosarcomas

International Nuclear Information System (INIS)

Joel, D.D.; Fairchild, R.G.; Laissue, J.A.; Saraf, S.K.; Kalef-Ezra, J.A.; Slatkin, D.N.

1990-01-01

The efficacy of boron neutron capture therapy (BNCT) for the treatment of intracerebrally implanted rat gliosarcomas was tested. Preferential accumulation of 10B in tumors was achieved by continuous infusion of the sulfhydryl borane dimer, Na4(10)B24H22S2, at a rate of 45-50 micrograms of 10B per g of body weight per day from day 11 to day 14 after tumor initiation (day 0). This infusion schedule resulted in average blood 10B concentrations of 35 micrograms/ml in a group of 12 gliosarcoma-bearing rats and 45 micrograms/ml in a group of 10 similar gliosarcoma-bearing rats treated by BNCT. Estimated tumor 10B levels in these two groups were 26 and 34 micrograms/g, respectively. On day 14, boron-treated and non-boron-treated rats were exposed to 5.0 or 7.5 MW.min of radiation from the Brookhaven Medical Research Reactor that yielded thermal neutron fluences of approximately 2.0 x 10(12) or approximately 3.0 x 10(12) n/cm2, respectively, in the tumors. Untreated rats had a median postinitiation survival time of 21 days. Reactor radiation alone increased median postinitiation survival time to 26 (5.0 MW.min) or 28 (7.5 MW.min) days. The 12 rats that received 5 MW.min of BNCT had a median postinitiation survival time of 60 days. Two of these animals survived greater than 15 months. In the 7.5 MW.min group, the median survival time is not calculable since 6 of the 10 animals remain alive greater than 10 months after BNCT. The estimated radiation doses to tumors in the two BNCT groups were 14.2 and 25.6 Gy equivalents, respectively. Similar gliosarcoma-bearing rats treated with 15.0 or 22.5 Gy of 250-kilovolt peak x-rays had median survival times of only 26 or 31 days, respectively, after tumor initiation

Modeling of the hot flow behavior of advanced ultra-high strength steels (A-UHSS) microalloyed with boron

Energy Technology Data Exchange (ETDEWEB)

Mejía, I., E-mail: imejia@umich.mx [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Altamirano, G.; Bedolla-Jacuinde, A. [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Cabrera, J.M. [Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB – Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Av. de las Bases de Manresa, 1, 08240 Manresa (Spain)

2014-07-29

In this research work, modeling of the hot flow behavior was carried out in a low carbon advanced ultra-high strength steels (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm). For this purpose, experimental stress–strain data of uniaxial hot-compression tests over a wide range of temperatures (1223, 1273, 1323 and 1373 K (950, 1000, 1050 and 1100 °C)) and strain rates (10{sup −3}, 10{sup −2} and 10{sup −1} s{sup −1}) were used. The stress–strain relationships as a function of temperature and strain rate were successfully described on the basis of the approach proposed by Estrin, Mecking, and Bergström, together with the classical Avrami equation and the conventional hyperbolic sine function. The analysis of the modeling parameters of the hot flow curves shows that boron additions to A-UHSS play a major role in softening mechanisms rather than on hardening. The peak stress (σ{sub p}) and steady-state stress (σ{sub ss}) values show a decreasing trend with increasing boron content, which indicates that boron additions promote a solid solution softening effect additional to that produced by DRX. The time for 50% recrystallization (t{sub 50%}) tends to increase with boron additions, revealing that boron additions cause a delay of the DRX kinetics during hot deformation. Similarly, the presence of boron in the steel decreases the apparent activation energy for recrystallization (Q{sub t}), indicating that boron additions accelerate the onset of DRX. The constitutive equations developed in this way provided an excellent description of the experimental hot flow curves.

A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

International Nuclear Information System (INIS)

Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar

2007-01-01

This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively

A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

Energy Technology Data Exchange (ETDEWEB)

Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey)], E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey)

2007-10-22

This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively.

Simulation of 10 A electron-beam formation and collection for a high current electron-beam ion source

Science.gov (United States)

Kponou, A.; Beebe, E.; Pikin, A.; Kuznetsov, G.; Batazova, M.; Tiunov, M.

1998-02-01

Presented is a report on the development of an electron-beam ion source (EBIS) for the relativistic heavy ion collider at Brookhaven National Laboratory (BNL) which requires operating with a 10 A electron beam. This is approximately an order of magnitude higher current than in any existing EBIS device. A test stand is presently being designed and constructed where EBIS components will be tested. It will be reported in a separate paper at this conference. The design of the 10 A electron gun, drift tubes, and electron collector requires extensive computer simulations. Calculations have been performed at Novosibirsk and BNL using two different programs, SAM and EGUN. Results of these simulations will be presented.

The radiation biology of Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

Coderre, J.A.

2003-01-01

Boron Neutron Capture Therapy (BNCT) produces a complex mixture of high and low-LET radiations in tissue. Using data on the biological effectiveness of these various dose components, derived primarily in small animals irradiated with thermal neutrons, it has been possible to express clinical BNCT doses in photon-equivalent units. The accuracy of these calculated doses in normal tissue and tumor will be reviewed. Clinical trials are underway at a number of centers. There are differences in the neutron beams at these centers, and differences in the details of the clinical protocols. Ideally, data from all centers using similar boron compounds and treatment protocols should be compared and combined, if appropriate, in a multi-institutional study in order to strengthen statistical analysis. An international dosimetry exchange is underway that will allow the physical doses from the various treatment centers to be quantitatively compared. As a first step towards the comparison of the clinical data, the normal brain tolerance data from the patients treated in the initial Brookhaven National Laboratory and the Harvard/MIT BNCT clinical trials have been compared. The data provide a good estimate of the normal brain tolerance for a somnolence syndrome endpoint, and provide guidance for setting normal brain tolerance limits in ongoing and future clinical trials. Escalation of the dose in BNCT can be accomplished by increasing the amount of the boron compound administered, increasing the duration of the neutron exposure, or both. The dose escalations that have been carried out to date at the various treatment centers will be compared and contrasted. Possible future clinical trials using BNCT in combination with other modalities will be discussed

Boron isotope fractionation in magma via crustal carbonate dissolution.

Science.gov (United States)

Deegan, Frances M; Troll, Valentin R; Whitehouse, Martin J; Jolis, Ester M; Freda, Carmela

2016-08-04

Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ(11)B values down to -41.5‰, reflecting preferential partitioning of (10)B into the assimilating melt. Loss of (11)B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports (11)B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ(11)B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

Boron isotope fractionation in magma via crustal carbonate dissolution

Science.gov (United States)

Deegan, Frances M.; Troll, Valentin R.; Whitehouse, Martin J.; Jolis, Ester M.; Freda, Carmela

2016-08-01

Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ11B values down to -41.5‰, reflecting preferential partitioning of 10B into the assimilating melt. Loss of 11B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports 11B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ11B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

Axial channeling of boron ions into silicon

International Nuclear Information System (INIS)

La Ferla, A.; Galvagno, G.; Raineri, V.; Setola, R.; Rimini, E.; Carnera, A.; Gasparotto, A.

1992-01-01

Channeling boron implants were performed into (100) and (110) silicon substrates in the energy range 80-700 keV. The dose ranged between 3.5x10 11 and 1x10 15 atoms/cm 2 . The axial channeling concentration profiles of implanted B + were compared with that obtained for incidence along the random direction of the crystal and with that obtained by implantation in amorphous silicon. The electrical and chemical boron distributions were obtained by spreading resistance and secondary ion mass spectrometry measurements, respectively. The inelastic stopping power, S c , was extracted from the experimental maximum ranges for the [100] and [110] axis. The energy dependence of the electronic stopping power is given by S e = KE p with p [100] = 0.469±0.010 and p [110] = 0.554±0.004. Simulations obtained by the MARLOWE code, using the Oen-Robinson impact parameter dependent formula, for the electronic energy loss reproduce quite well the experimental depth profiles. (orig.)

Determination of boron spectrophotometry in thorium sulfate