The quality of environmental impact statements and environmental impact assessment practice in Bangladesh

This paper investigates the quality of environmental impact statements (EISs) and gives us an understanding about the performance of environmental impact assessment (EIA) practice in Bangladesh. EIA has been formally practised in Bangladesh since 1995.However, no study has yet been conducted on the quality of EISs. This study fills this gap. This empirical study shows that the quality of EISs in Bangladesh is ‘just satisfactory’ only. A significant proportion of EISs (34%) are still unsatisfactory. Finally, possible factors affecting the quality of EISs are examined and measures to improve the quality of EISs are recommended. The findings will be useful to EIA practitioners and other stakeholders in Bangladesh. This study will also provide a general guideline for other developing countries with similar socio-economic context.     

Oil–water two‐phase flow in microchannels: Flow patterns and pressure drop measurements

This paper investigates oil–water two‐phase flows in microchannels of 793 and 667 µm hydraulic diameters made of quartz and glass, respectively. By injecting one fluid at a constant flow rate and the second at variable flow rate, different flow patterns were identified and mapped and the corresponding two‐phase pressure drops were measured. Measurements of the pressure drops were interpreted using the homogeneous and Lockhart–Martinelli models developed for two‐phase flows in pipes. The results show similarity to both liquid–liquid flow in pipes and to gas–liquid flow in microchannels. We find a strong dependence of pressure drop on flow rates, microchannel material, and the first fluid injected into the microchannel.     

Cheddar Cheese Ripening and Flavor Characterization: A Review

Cheddar cheese is a biochemically dynamic product that undergoes significant changes during ripening. Freshly made curds of various cheese varieties have bland and largely similar flavors and aroma and, during ripening, flavoring compounds are produced that are characteristic of each variety. The biochemical changes occurring during ripening are grouped into primary events including glycolysis, lipolysis, and proteolysis followed by secondary biochemical changes such as metabolism of fatty acids and amino acids which are important for the production of secondary metabolites, including a number of compounds necessary for flavor development. A key feature of cheese manufacture is the metabolism of lactose to lactate by selected cultures of lactic acid bacteria. The rate and extent of acidification influence the initial texture of the curd by controlling the rate of demineralization. The degree of lipolysis in cheese depends on the variety of cheese and may vary from slight to extensive; however, proteolysis is the most complex of the primary events during cheese ripening, especially in Cheddar-type cheese.     

Transmission Power Control Aware Routing in Cognitive Radio Ad Hoc Networks

Abstract—Cognitive radio technology has drawn much attention since it is a promising candidate to efficiently utilize the scarce radio resources. However, cognitive radio introduces new challenges in the protocol stacks in wireless networks. This paper proposes a routing protocol for Cognitive Radio Ad Hoc Networks (CRAHNs), called Transmission Power Control aware AODV (TPC-AODV). TPC-AODV is based on Ad hoc On Demand Distance Vector (AODV) routing protocol. The main objectives of TPC-AODV are to avoid interruption of primary users’ communication and to support basic Quality of Service for secondary users. TPC-AODV takes inputs from both secondary users’ application requirements and the channel condition after spectrum sensing. These inputs enable secondary users’ communication with specific transmission power on the selected channel. Our simulation results show that TPC-AODV improves network performance in terms of throughput and delay compared to AODV in CRAHNs.     

Performance of Layered Steered Space–Time Codes in Wireless Systems

Layered Steered Space–Time Codes (LSSTC) is a recently proposed multiple-input multiple-output (MIMO) system that combines the benefits of vertical Bell Labs space–time (VBLAST) scheme, space–time block codes (STBC) and beamforming. In this paper, we derive the error performance and capacity of a single-user LSSTC system. The analysis is general enough to any layer ordering and modulation schemes used. In addition, the derived analysis is general for any LSSTC structure in which layers may have different number of antenna arrays and may be assigned power according to any power allocation. Furthermore, we analytically investigate the tradeoff between the main parameters of the LSSTC system, i.e., diversity, multiplexing and beamforming. Our results give recursive expressions for the probability of error for LSSTC which showed nearly perfect match to the simulation results. Results have also revealed the possibility of designing an adaptive system in which it was shown that combining beamforming, STBC, and VBLAST has better performance than VBLAST at high SNR range.     

Gamification Solutions to Enhance Software User Engagement—A Systematic Review

Gamification is the use of video-game mechanics and elements in nongame contexts to enhance user engagement and performance. The purpose of this study is to conduct a systematic review to have an in-depth investigation into the existing gamification solutions targeted at solving user engagement problems in different categories of software. We carried out this systematic review by proposing a framework of gamifying process, which is the basis for comparison of existing gamification solutions. In order to report the review, the primary studies are categorized according to the following: a) gamified software and their platforms; b) elements of the gamifying process; c) gamification solutions in each software type; d) gamification solutions for software user engagement problems; e) gamification solutions in general; and f) effects of gamification on software user engagement and performance. Based on the search procedure and criteria, a total of 78 primary studies were extracted. Most of the studies focused on educational and social software, which were developed for web or mobile platforms. We concluded that the number of studies on motivating users to use software content, solving problems in learning software, and using real identity is very limited. Furthermore, few studies have been carried out on gamifying the following software categories: productivity software, cloud storage, utility software, entertainment software, search engine software, tool software, fitness software, software engineering, information worker software, and health-care software. In addition, a large number of gamification solutions are relatively simple and require improvement. Thus, for future studies, researchers can work on the items discovered in this review; they can improve the quality of the current gamified systems by using a wide variety of game mechanics and interface elements, utilizing a combination of contextual types of rewards and giving users the ability to use received rewards “in-game” and “out-game.”     

A Review on Hybrid Fillers in Rubber Composites

This review article is aimed at reporting the recent development of hybrid fillers used in vulcanized rubber. This review will consider the synergistic effect of rubber hybrid composites that consist exclusively of conventional fillers; carbon black and/or silica as the primary filler, which are combined with secondary fillers from various sources. The discussions are mainly focused on the analyses and comparisons of the curing characteristics, morphology, and mechanical properties of the rubber composite-filled hybrid fillers. The compatibility and the existence of synergistic effects between the different types of fillers show the potential for development and application in rubber industries.     

Enhanced hybrid image security algorithms for high definition images in multiple applications

Protection of multimedia information from different types of attackers has become important for people and governments. A high definition image has a large amount of data, and thus, keeping it secret is difficult. Another challenge that security algorithms must face with respect to high definition images in medical and remote sensing applications is pattern appearances, which results from existing regions with high density in the same color, such as background regions. An encryption and hiding based new hybrid image security systems are proposed in this paper for the purpose of keeping high definition images secret. First, one hiding method and two encryption methods are used in two hybrid algorithms. The new hiding algorithm proposed here starts by applying reordering and scrambling operations to the six Most Significant Bit planes of the secret image, and then, it hides them in an unknown scene cover image using adding or subtracting operations. Second, two different ciphering algorithms are used to encrypt the stego-image to obtain two different hybrid image security systems. The first encryption algorithm is based on binary code decomposition, while the second algorithm is a modification of an advanced encryption standard. After evaluating each hybrid algorithm alone, a comparison between the two hybrid systems is introduced to determine the best system. Several parameters were used for the performance, including the visual scene, histogram analysis, entropy, security analysis, and execution time.