Monte Carlo study of spatial resolution of the scintillation camera

The aim of this study was to evaluate the influence of different entrance surface treatments of the scintillator on the intrinsic spatial resolution of a scintillation camera.The primary scintillation light reflection on the entrance surface of a scintillator may be affected by the optical coating of the entrance surface,resulting in either spatial resolution or system detection efficiency degradation.A Monte Carlo simulation model,based on Geant4 codes,was developed in order to study the scintillation ligh...     

INFLUENCE OF APPLE JUICE TREATMENTS ON THE CIDER MAKING PROCESS

This study was conducted to examine the influence of the following apple juice treatments on different parameters of cidermaking process: sulphiting (50 mg/L of total S0₂), clarification with pectolytic enzymes (Ultrazym 100 G, 3g/hL), and bentonite fining (lOOg/hL). The different treatments slowed down alcoholic fermentation, the greatest effect being found for the combination of the three treatments. With respect to malolactic fermentation, must sulphiting, with or without the other two treatments, delayed this process, which took place after alcoholic fermentation. The low levels of lactic acid bacteria during this period can explain this delay. The only treatment that had any significant influence on volatile acidity was sulphiting, either on its own or in combination with the other treatments. Thus lower acetic acid levels were detected in ciders treated with SO₂ .     

Direct Ni Electroless Metallization of Poly(etherimide) without Using Palladium as a Catalyst

ELECTROLESS METALLIZATION of insulatingmaterials is currently used in industry since severaldecades.In its most common applications it consists ina redox reaction between Ni(+2)or Cu(+2)ions and astrong reducer(respectively hypophosphite,H2PO2,forNi(+2)and formaldehyde,HCHO,for Cu(+2))bothcontained in the same solution.The reaction initiationis generally catalyzed by palladium,then the redoxreaction goes on thanks to the remarkable property ofNi and Cu in their metallic state to …     

Introduction to the special section on evidence-based psychological treatments for older adults.

Psychology has a strong tradition as a science-based discipline. This tradition has also been strong in the subfields of geropsychology and clinical psychology. The convergence of these traditions leads to an expectation that mental health and aging practices will be theoretically sound and empirically tested. This Psychology and Aging Special Section on Evidence-Based Psychological Treatments for Older Adults presents findings which demonstrate that there are a number of evidence-based treatments that can contribute to exemplary care of older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Heat Treatments on Steels for Bearing Applications

AISI 52 100, 440C, REX20, and Crucible CRU80 steel samples were exposed to 16 different heat treatments to vary the levels of retained austenite. Rockwell C hardness measurements, optical microscopy, and compression testing were used to compare the properties of the different steels.     

Assessment and treatment of sleep disorders in older adults: A review for rehabilitation psychologists.

Recent research has led to significant progress in the assessment and treatment of sleep disturbance in older adults. Similar advances have been made with sleep disorders secondary to age-related chronic illness. The assessment and treatment of sleep disorders encompasses numerous behavioral aspects. Thus, rehabilitation psychologists are ideally positioned to help apply these new advances to the growing number of older adult patients in the rehabilitation setting. The authors provide an overview of age and disease-related sleep disorders. They provide details for implementation of behavioral treatments for geriatric insomnia that is comorbid with chronic illness. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

钢筋模板一体化剪力墙受弯性能试验研究

为提高装配式建筑施工速度,减少施工工序,提出了一种装配式建筑结构体系——钢筋模板一体化剪力墙结构体系,其两侧采用20mm厚高性能纤维砂浆板作为模板,钢筋骨架配置于中部空腔内,具有自重轻、易于运输、安装等特点。通过对4个剪力墙开展拟静力试验,研究了剪力墙的受力性能和连接界面的性能。研究结果表明：一体化剪力墙的受弯承载力、刚度和延性与钢筋混凝土剪力墙基本相当,能够满足“等同现浇”的设计要求;模板与混凝土整体性良好,剪力墙屈服时模板与混凝土保持整体,破坏(加载点位移角θ>1/60)时模板未发生剥离,模板与后浇混凝土保持共同受力;连接件间距为400mm、预制模板内侧自然成型的一体化剪力墙的模板构造满足受力要求。模板拉毛处理和连接件的加密具有延缓结合面开裂的作用,对剪力墙的承载力、刚度、延性等基本无影响。     

Optimized AISI 304 steel nitriding in inductive RF N2-H2 plasmas

Optimal surface nitriding is closely related to plasma chemical composition. The effects of Plasma-Immersion Ion Implantation (PIII) nitriding with 15% N₂+85% H₂ type mixtures have been studied. A simplified PIII facility was assembled around an evacuated Pyrex cylindrical 500 mm long reactor with a 190 mm inner diameter, over which a 3.2 mm wide antenna was coaxially wound with a 240 mm inner diameter. The system was supplied by a 13.56 MHz RF generator whose electric component developed the plasma discharge. After the admission of the gas mixture to the reactor vessel the breakdown took place within 5-15 Pa work pressure and 450-500W RF power. The main plasma parameters were characterized including a 1.8 × 10¹⁸ to 3.1 × 10¹⁸ m⁻³ density by means of double Langmuir probes. An additional DC power supply was selected in order to bias AISI 304 stainless steel samples with a view to improving the steel hardness properties without compromising its corrosion resistance. The samples treated at different temperatures and for several periods, were evaluated by means of X-ray diffraction (XRD), which indicated the formation of nitrides, identified as Fe₃NiN and FeNiN and can be associated with the enhanced austenitic phase of the stainless steel. Scanning electron microscopy (SEM) assessed the atomic percentages of nitrogen both on the sample surface and through their cross-section. Vickers microhardness (HV) tests exhibited up to a 6-7 times increase at a 500g load. Finally, Raman spectroscopy studies established four active modes at 215, 267, 385 and 490 cm⁻¹ with temperatures between 400 and 500 °C.     

Effects of treatment with low molecular weight phenol formaldehyde resin on the surface characteristics of oil palm (Elaeis quineensis) stem veneer

Even though oil palm (Elaeis quineensis) stem (OPS) is highly potential as an alternative raw material in wood industry, it possesses some inferior characteristics. One of the critical weaknesses is a high degree of veneer surface roughness that resulted in high resin consumption during plywood manufacture. The objective of this study was to investigate effects of treatment with low molecular weight phenol formaldehyde (LMWPF) resin on the wettability and surface roughness of OPS veneer. OPS veneers were segregated into two categories namely outer and inner layer veneer, prior to soaking in LMWPF resin solution to obtain weight percent gain of 16–20%. The wettability of OPS veneers was assessed with contact angle measurement according to the sessile drop method. The veneer surface roughness was evaluated by determining the average roughness (R_a), mean peak-to-valley height (R_z), and maximum roughness (R_max) using a stylus profilometer in accordance with DIN standard 4768. The results show that the effect of LMWPF resin treatment on the surface roughness of the veneers is statistically significant. The technique used in the study was able to enhance the surface properties as well as improved the physical and mechanical properties of OPS plywood.     

The microstructure and mechanical properties of friction stir welded Al–Zn–Mg alloy in as welded and heat treated conditions

High strength aluminium alloys generally present low weldability because of the poor solidification microstructure, porosity in the fusion zone and loss in mechanical properties when welded by fusion welding processes which otherwise can be welded successfully by comparatively newly developed process called friction stir welding (FSW). This paper presents the effect of post weld heat treatment (T₆) on the microstructure and mechanical properties of friction stir welded 7039 aluminium alloy. It was observed that the thermo-mechanically affected zone (TMAZ) showed coarser grains than that of nugget zone but lower than that of heat affected zone (HAZ). The decrease in yield strength of welds is more serious than decrease in ultimate tensile strength. As welded joint has highest joint efficiency (92.1%). Post weld heat treatment lowers yield strength, ultimate tensile strength but improves percentage elongation.