An investigation of the drivers,barriers, and incentives for environmental management systems in the Malaysian food and beverage industry

Clean Technologies and Environmental Policy - Food production and consumption is one of the major causes of global environmental degradation. One way to address environmental impacts in the food...     

RB Regulates DNA Double Strand Break Repair Pathway Choice by Mediating CtIP Dependent End Resection

Inactivation of the retinoblastoma tumor suppressor gene (RB1) leads to genome instability, and can be detected in retinoblastoma and other cancers. One damaging effect is causing DNA double strand breaks (DSB), which, however, can be repaired by homologous recombination (HR), classical non-homologous end joining (C-NHEJ), and micro-homology mediated end joining (MMEJ). We aimed to study the mechanistic roles of RB in regulating multiple DSB repair pathways. Here we show that HR and C-NHEJ are decreased, but MMEJ is elevated in RB-depleted cells. After inducing DSB by camptothecin, RB co-localizes with CtIP, which regulates DSB end resection. RB depletion leads to less RPA and native BrdU foci, which implies less end resection. In RB-depleted cells, less CtIP foci, and a lack of phosphorylation on CtIP Thr847, are observed. According to the synthetic lethality principle, based on the altered DSB repair pathway choice, after inducing DSBs by camptothecin, RB depleted cells are more sensitive to co-treatment with camptothecin and MMEJ blocker poly-ADP ribose polymerase 1 (PARP1) inhibitor. We propose a model whereby RB can regulate DSB repair pathway choice by mediating the CtIP dependent DNA end resection. The use of PARP1 inhibitor could potentially improve treatment outcomes for RB-deficient cancers.     

Selective hydrogenation of nitriles to imines over a multifunctional heterogeneous Pt catalyst

Imines and their derivatives are versatile synthetic intermediates for the industrial preparation of both bulk and fine chemicals and for pharmaceuticals, but preparing these compounds efficiently through direct hydrogenation of nitriles are hindered by overhydrogenation to secondary amines. Here we report a highly efficient multifunctional catalyst system for selective hydrogenation coupling of nitriles to secondary imines using a heterogeneous Pt catalyst that was deposited on a nickel‐based metal‐organic framework (MOF) containing DABCO. The catalyst showed excellent synergy in promoting the hydrogenation of a variety of nitriles, giving significantly improved activity and selectivity (up to >99% yield) even under atmospheric pressure of H₂. It is suggested that the Lewis base (DABCO) sites on the Ni‐MOF inhibit further hydrogenation of the imines. The influence of H₂ pressure, reactant concentration, stirring speed, and reaction temperature was investigated. The kinetics and mechanism of hydrogenation of benzonitrile (BN) by the Pt/Ni‐MOF catalyst has been studied. The reaction showed a first‐order dependence on both BN concentration and H₂ pressure. A kinetic model was proposed based on the mechanism of nitriles hydrogenation and compared with experimental observations. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3565–3576, 2014     

钻进参数用于香港复杂风化花岗岩地层的界面识别

在采用仪器钻进系统对复杂风化花岗岩地层界面进行成功识别的基础上,在复杂风化花岗岩场址的勘探中进行进一步应用和检验。在该风化花岗岩地层中,强风化与中等风化花岗岩交错,地层特征相当复杂。试验采用R–20液压回转式钻机,并安装数字式钻孔过程监测系统,在钻孔过程中对穿孔参数进行自动采集。对穿孔参数的定性和定量分析表明,在此地层中,有效轴压力、钻具转速、冲洗压力、钻头位移及穿孔速率等监测参数在界面处亦具有明显的涨落,说明这些参数与界面处岩石强度的变化具有很好的响应特征,能可靠地揭示复杂地层的变化。同时,采用变斜率法对地层中的主、次界面进行识别。t检验表明,仪器钻进系统对岩土界面识别的置信度为99%。     

Indoor air quality and energy performance of air-conditioned office buildings in Singapore

An integrated indoor air quality (IAQ)-energy audit methodology has been developed in this study in Singapore, which provides a rigorous and systematic method of obtaining the status-quo assessment of an 'IAQ signature' in a building. The methodology entails a multi-disciplinary model in obtaining measured data pertaining to different dimensions within the built environment such as the physical, chemical, biological, ventilation, and occupant response characteristics. This paper describes the audit methodology and presents the findings from five air-conditioned office buildings in Singapore. The research has also led to the development of an indoor pollutant standard index (IPSI), which is discussed in this paper. Other performance indicators such as, the ventilation index and the energy index as well as the building symptom index (BSI) are also presented and discussed in the context of an integrated approach to IAQ and energy. Several correlation attempts were made on the various symptoms, indoor air acceptability, thermal comfort, BSI and IPSI, and while BSI values are found to correlate among them as well as with IAQ and THERMAL COMFORT acceptability, no such correlation was observed between BSI and IPSI. This would suggest that the occupants' perception of symptoms experienced as well as environmental acceptability is quite distinct from IAQ acceptability determined from empirical measurements of indoor pollutants, which reinforces the complex nature of IAQ issues.     

一种用于岩石材料微裂纹观察的复型技术

介绍了一种用于岩石材料微裂纹观察的复型技术。这种半透明的试样表面复型可有效复制宽度大于0.2μm的微观裂纹以及矿物颗粒的微结构特征，并可方便地用于光学显微镜和扫描电镜下观察。它的最大特点是不仅能精确复制岩样的表面裂纹，同时还能提供足够多的信息以鉴别矿物颗粒。应用表明：对于岩石材料的微破裂研究，特别对于矿物颗粒的破坏行为与岩石破坏的关系研究，它是一种方便而有效的方法。     

蓄水期库岸古滑坡的水动力学响应监测——以三峡库区泄滩滑坡为例

水库岸坡失稳是伴随水电工程建设而产生的一种地质灾害，一般认为主要是由于水库蓄水或运营导致岸坡水动力条件的不利演化造成的。国内外水库岸坡失稳的实例很多，但是岸坡的水动力条件演化过程主要以渗流计算所获得的渗流场作为依据，缺乏系统完整的现场监测资料。以三峡水库蓄水为契机，在湖北秭归县泄滩古滑坡体上建立了一套自动水文监测系统，监测内容包括水库水位、滑坡体水位、渗压与降雨量等。从监测成果来看，岸坡的水位(或渗压)上升速度明显滞后于库水位上升速度，滞后时间与岸坡的渗透性有关，滑带、滑坡影响带和基岩的渗透性相对较弱，滞后时间较长，但是滑坡体的渗透性良好，滞后时间较短；水位观测井的观测成果存在误导，需要结合观测井结构进行分析，建议尽可能使用标准管结构；降雨引起的滑坡体水位上升量和滞后时间与降雨强度关系密切，降雨强度越大水位上升量越大，水位开始上涨的时间越短。因此，对降雨的影响分析有必要考虑雨型，确定合适的基准时间单位。就泄滩滑坡而言，以小时为基本时间单位较为合适。     

香港花岗岩单轴压缩时的操作演化

An investigation is reported on the characteristics of progressive failure of Hong Kong granite. Uniaxial compression tests are performed on a number of Hong Kong granite specimens with the MTS 815.04 testing machine.Acoustic emission signals are recorded to trace the evolution of damages. Parametric studies on the effect of grain size are attempted. The results show that the increase in grain size will reduce the brittleness during failure. In addition, discussion is extended to the grain size effect on the stress thresholds of crack closure, crack initiation and crack damage. The RFPA^2D code is also used to observe the failure characteristics of brittle rocks such as granite. Microscopic tensile failure is dominant in the ultimate failure of all the uniaxially compressed models. The crack initiation threshold is also determined by the numerical approach. The failure of coarse-grained models seems more ductile.     

Local thermal sensation and comfort study in a field environment chamber served by displacement ventilation system in the tropics

This paper presents a study of local thermal sensation (LTS) and comfort in a field environmental chamber (FEC) served by displacement ventilation (DV) system. The FEC, 11.12 m (L)×7.53 m (W)×2.60 m (H), simulates a typical office layout. A total of 60 tropically acclimatized subjects, 30 male and 30 female, were engaged in sedentary office work for 3 h. Subjects were exposed to three vertical air temperature gradients, nominally 1, 3 and 5 K/m, between 0.1 and 1.1 m heights and three room air temperatures of 20, 23 and 26 °C at 0.6 m height. The objective of this study is to investigate the mutual effect of local and overall thermal sensation (OTS) and comfort in DV environment. The results show that in a space served by DV system, at OTS close to neutral, local thermal discomfort decreased with the increase of room air temperature. The OTS of occupants was mainly affected by LTS at the arm, calf, foot, back and hand. Local thermal discomfort was affected by both LTS and OTS. At overall cold thermal sensation, all body segments prefer slightly warm sensation. At overall slightly warm thermal sensation, all body segments prefer slightly cool sensation.     

CaO-MgO-Al2O3-SiO2 corrosion behavior of SrZrO3-La2Ce2O7 composite ceramics

In this work, the corrosion behavior, interaction products, and the corrosion mechanism of (1-x)SrZrO₃-xLa2Ce2O7(x = 0.3, S7L3; x = 0.5, S5L5; x = 0.7, S3L7) composite bulks after CaO-MgO-Al₂O₃-SiO₂ (CMAS) attack at 1250°C for 1, 4, and 12 h were investigated, respectively. The molten CMAS and the bulks rapidly interacted and generated a dense reaction layer, which mainly composed of La-Ce apatite, Ce₂Zr₂O_7.04, ZrO₂ with some Ce, Ca, Si, Mg, and Al elements preventing CMAS from continuous penetration effectively. The formation of CMAS self-crystallizing products such as Ca₂Al₂SiO₇ gehlenite and Mg-Al spinel with high melting points increased the viscosity of CMAS. The elements in the ceramic also diffused into the molten CMAS and formed Ce₂Zr₂O_7.04 and La₂Ce₂O₇, increasing the melt viscosity and blocking the penetration channel of the molten CMAS. The S5L5 bulk has the best corrosion resistance against CMAS attacks.