Surface area and pore structure of stannic oxide gel from organic vapour adsorption

Surface area measurements were performed on stannic oxide gel and its thermal dehydration products obtained both in vacuo and in presence of air in the temperature range 100–600°C by benzene and carbon tetrachloride adsorption at 35°C. The presence or absence of air is found to impose changes in the surface area and consequently vary the pore structure of the solid material. Pore size analyses for both micro- and mesopores are performed. The low temperature samples are characterised by the presence of micropores only. At 350°C widening of pores commences and at higher temperatures the results indicate the existence of pores of “submicro” dimensions together with the mesopores. These changes in pore structure go in parallel with the gradual development of the crystalline cassiterite structure.     

Building and querying e-catalog networks using P2P and data summarisation techniques

One of the critical issues in Web-based e-commerce has been how to efficiently and effectively integrate and query heterogeneous, diverse e-catalogs. We propose an integration framework for building and querying catalogs. Our approach is based on a hybrid of peer-to-peer data sharing paradigm and Web-services architecture. Peers in our system serve as domain-specific data integration mediators. Links between peers are established based on the similarity of the domain they represent. The relationships are used for routing queries among peers. As the number of catalogs involved grow larger, the need for filtering irrelevant data sources will become increasingly high. We apply a summarisation technique to summarise the content of catalogs. The summaries are used to pre-selecting data sources that are relevant to a user query. We use terms e-catalog and catalog interchangeably.     

数字信号处理器与仿真软件接口设计

文中针对DSP与计算机软硬件接口能力差,无法将其丰富的资源为开发者所利用的现象,提出基于MATLAB设计和DSP汇编语言编写FIR滤波器的方案。介绍利用MATLAB从文件中获得数据,通过接口函数传给DSP进行运算处理的过程。实践证明,这种方案准确度高、稳定性好,易于移植,具有较强的实用性与灵活性。     

Engaging construction stakeholders with sustainability through a knowledge harvesting platform

With the new regulations and policies related to climate change, the construction industry has been put under pressure to increase the sustainability of its practices. Many organisations are now adapting their practices to meet government legislative targets (e.g. reducing carbon emissions) and consider the environmental, social and economic performance of buildings. In addition, the sustainable construction is also a rapidly changing field, with technological advances, changes in legislation and increasingly educated clients driving the industry to constantly adapt to remain competitive. This represents a key problem for construction professionals as they must continually be aware of new information, best practices, technologies and changing legislation (at a local, national and international level) which are often disseminated from different organisations/individuals through dispersed media.     

Reactions of 4-Benzylidene-3-methyl-5-oxopyrazoline,pyrazole blue,and rubazoic acid with GRIGNARD reagents

While 4-benzylidene-3-methyl-5-oxopyrazoline 1 and pyrazole blue 2 with GRIGNARD reagents gave 1,4-addition, rubazoic acid 3 gave 1, 2-addition on both sides with ethylmagnesium bromide.     

Minimising the makespan in the two-machine job shop problem under availability constraints

Classical scheduling problem assumes that machines are available during the scheduling horizon. This assumption may be justified in some situations but it does not apply if maintenance requirements, machine breakdowns or other availability constraints have to be considered. In this paper, we treat a two-machine job shop scheduling problem with one availability constraint on each machine to minimise the maximum completion time (makespan). The unavailability periods are known in advance and the processing of an operation cannot be interrupted by an unavailability period (non-preemptive case). We present in our approach properties dealing with permutation dominance and the optimality of Jackson's rule under availability constraints. In order to evaluate the effectiveness of the proposed approach, we develop two mixed integer linear programming models and two schemes for a branch and bound method to solve the tackled problem. Computational results validate the proposed approach and prove the efficiency of the developed methods.     

Droplet Combustion Experiments Aboard the International Space Station

This paper summarizes the first results from isolated droplet combustion experiments performed on the International Space Station (ISS). The long durations of microgravity provided in the ISS enable the measurement of droplet and flame histories over an unprecedented range of conditions. The first experiments were with heptane and methanol as fuels, initial droplet droplet diameters between 1.5 and 5.0 m m, ambient oxygen mole fractions between 0.1 and 0.4, ambient pressures between 0.7 and 3.0 a t m and ambient environments containing oxygen and nitrogen diluted with both carbon dioxide and helium. The experiments show both radiative and diffusive extinction. For both fuels, the flames exhibited pre-extinction flame oscillations during radiative extinction with a frequency of approximately 1 H z. The results revealed that as the ambient oxygen mole fraction was reduced, the diffusive-extinction droplet diameter increased and the radiative-extinction droplet diameter decreased. In between these two limiting extinction conditions, quasi-steady combustion was observed. Another important measurement that is related to spacecraft fire safety is the limiting oxygen index (LOI), the oxygen concentration below which quasi-steady combustion cannot be supported. This is also the ambient oxygen mole fraction for which the radiative and diffusive extinction diameters become equal. For oxygen/nitrogen mixtures, the LOI is 0.12 and 0.15 for methanol and heptane, respectively. The LOI increases to approximately 0.14 (0.14 O ₂/0.56 N ₂/0.30 C O ₂) and 0.17 (0.17 O ₂/0.63 N ₂/0.20 C O ₂) for methanol and heptane, respectively, for ambient environments that simulated dispersing an inert-gas suppressant (carbon dioxide) into a nominally air (1.0 a t m) ambient environment. The LOI is approximately 0.14 and 0.15 for methanol and heptane, respectively, when helium is dispersed into air at 1 atm. The experiments also showed unique burning behavior for large heptane droplets. After the visible hot flame radiatively extinguished around a large heptane droplet, the droplet continued to burn with a cool flame. This phenomena was observed repeatably over a wide range of ambient conditions. These cool flames were invisible to the experiment imaging system but their behavior was inferred by the sustained quasi-steady burning after visible flame extinction. Verification of this new burning regime was established by both theoretical and numerical analysis of the experimental results. These innovative experiments have provided a wealth of new data for improving the understanding of droplet combustion and related aspects of fire safety, as well as offering important measurements that can be used to test sophisticated evolving computational models and theories of droplet combustion.     

Small heat shock proteins and their role in meat tenderness: A review

The eating quality of meat is a result of complex interactions between the biological traits and biochemical processes during the conversion of muscle to meat. It was hypothesised that muscles inevitably engage towards apoptotic cell death due to the termination of oxygen and nutrient supply to the muscle following exsanguination. Thus, factors that regulate the process of apoptotic cell death of muscle cells are believed to ultimately influence meat quality. Proteomic studies have associated the regulation of small heat shock proteins (sHSPs) with various meat quality attributes including tenderness, colour, juiciness and flavour. Due to the anti-apoptotic and chaperone functions of sHSPs, they are proposed to be involved with the eating quality of meat. In this review, we discuss the possible chaperone and anti-apoptotic role of sHSPs during the conversion of muscle to meat and consider the repercussions of this on the development of meat tenderness.     

Ultra-fast freezing and low storage temperatures are not necessary to maintain the functional properties of manufacturing beef

The effects of freezing rates and subsequent storage temperatures on the functional properties of meat were assessed. In the first trial, 24 Semitendinosus muscles were allocated to four freezing treatments to determine the effect of freezing rate alone (no frozen storage) on the functional properties of thawed muscle proteins. In the second trial, the effect of freezing rate, storage temperature and time were determined: 24 semimembranosus muscles were assigned to 30 treatment combinations using an incomplete factorial design with two freezing rates × three storage temperatures × five storage times. All samples individually sealed in water impermeable bags were thawed in water at 10?°C and then analysed. The rate of freezing alone in both trials and for both muscles had no effect on protein solubility; sulphydryl content; surface hydrophobicity; emulsion activity index or meat colour. Slowly frozen semimembranosus had more drip than fast frozen muscles. Semimembranosus muscle sarcoplasmic protein solubility increased and myofibrillar protein solubility decreased with storage temperature below -18?°C. Storage temperature did not affect the other attributes measured. Functional properties were mainly affected by storage time and the interaction between storage time and freezing rate. It is concluded that the current practice of blast freezing and storage at -18 to 20?°C is sufficient to maintain the quality of manufacturing beef.     

Cooked sausage batter cohesiveness as affected by sarcoplasmic proteins

In the first trial, m. semitendinosus and m. biceps femoris were held at 0, 10 and 35?°C until they entered rigor, and in the second trial, minced m. semitendinosus was washed in water for 15, 30, 45 or 60 min. The samples from both the trials were then used to make a finely comminuted sausage batter. Soluble sarcoplasmic protein (SSP) levels decreased with increasing rigor temperature (P < 0.05) or washing (P < 0.01). Cooked batter shear stress was not affected by SSP level, but batter shear strain decreased with the decreasing SSP level associated with an increasing rigor temperature (P < 0.05) or washing (P < 0.01). Reducing the SSP content lowered the cook yield (P < 0.05) and emulsion stability (P < 0.01) of the batter from the washed samples compared to that of controls. The results suggest that sarcoplasmic proteins are important in determining the strain values (cohesiveness) of cooked sausage batter.