Guidelines for the application of recycled concrete aggregate in the Egyptian construction Industry

Construction industry is one of the most important fractions of economy worldwide. This industry consumes enormous amounts of raw materials and produces considerable waste. The optimization of construction material usage not only saves costs but also can significantly contribute towards sustainable development. The concept of recycling the construction and demolition rubble is being addressed in this study as a solution. The recycling of concrete, resulting from both the construction activities and the demolition activities, in order to be used as a source of aggregate is being focused upon in this study. Although the idea of using recycled concrete has been implemented widely in the United States and European construction industries, one can find that the idea is still limited in most of the developing countries and Egypt is one of these nations as well. This study raises the questions of: Why the use of recycled concrete, as a source of aggregate, is still limited in Egypt and why are contractors and consultants still not encouraged to adopt the Recycled Concrete Aggregate notion even in small construction jobs? In order to address these questions, a survey has been performed within a wide range of entities that are involved in the construction and demolition waste industries in Egypt. Most of those entities have figured out that the absence of the codes of practices, field experiences, and the know-how, and the environmental and economic concerns are some of the main reasons behind these questions. The study introduces the problem and an overview on the situation in Egypt concerning the recycling of concrete. It tackles the development of the concept of concrete recycling and presents the past world experiences in the field of concrete recycling. Moreover, a survey questionnaire is being presented covering the situation in the Egyptian construction and demolition waste industries. It also provides the know-how of recycling concrete in the form of the layout of production plants, recycling process and crushing mechanisms. In addition, the material (Recycled Concrete Aggregate) performance and the environmental and economic concerns in recycling concrete are being tackled in the study. The study attempts to develop both an economic model to assess the national savings that could result from recycling concrete waste and also to evaluate the viability of creating markets for recycled concrete aggregate. Moreover, some specification limits for recycled aggregate properties are being proposed by the study. The overriding conclusions of the study reveal that the government should address codes of practices and should also address taxes, levies, and subsidies in order to encourage the application of concrete recycling. Some recommendations for future studies are also presented

Enhancing Query Processing on Stock Market Cloud-based Database

Cloud computing is rapidly expanding because it allows users to save the development and implementation time on their work. It also reduces the maintenance and operational costs of the used systems. Furthermore, it enables the elastic use of any resource rather than estimating workload, which may be inaccurate, as database systems can benefit from such a trend. In this paper, we propose an algorithm that allocates the materialized view over cloud-based replica sets to enhance the database system\u27s performance in stock market using a Peer-to-Peer architecture. The results show that the proposed model improves the query processing time and network transfer cost by distributing the materialized views over cloud-based replica sets. Also, it has a significant effect on decision-making and achieving economic returns

Stainless Steel Sponge as a Carrier for Immobilization of Rhizopus nigricans Isolate used for Biotrnsformation of Progesterone to 11α-hydroxprogesterone

Biotransformation is an important tool to provide the intermediate for steroid manufacturing. Stainless steel sponge was used as a carrier to immobilize an isolate of Rhizopus nigricans which can convert progesterone to 11α-hydroxyprogesterone (11α-HP). The conversion ability of the isolate was measured. The immobilized cells showed the ability to withstand the stress of the biotransformation process. Different parameters were studied to achieve the optimum conditions for 11α-HP production. The immobilized cells were reused for seven successive runs and maintained high bioconversion abilities during the first two runs then lost the conversion ability in seventh run

Enhancement of QoS in voice-enabled networks using combination of MPLS and DiffServ

At its beginnings, the Internet Protocol was not meant for real-time applications such as voice and video. These conventional IP networks were limited to providing only best-effort QoS model which implies no QoS. Now voice traffic has been transmitted to IP-based networks instead of the conventional Public Switched Telephone Network (PSTN). Therefore, early adopters of this technology have noticed that for voice traffic to function as well as on conventional IP-based network as in PSTN, the transport techniques used by the IP-based network needed some additional policies and technique in place to accommodate the requirements of real-time data traffic. DiffServ is another QoS model used in IP networks, which differentiates IP traffic into classes each with certain priority. Implementing DiffServ, alone, can meet the SLA requirement in term of providing different QoS techniques based on the traffic type, but cannot ensure bandwidth, perapplication basis, so congested path may cause jitter, end to end delay or packet loss. MPLS was developed to combine the advantages of the connectionless layer 3 routing and the connection-oriented layer 2 forwarding, and provides per-hop data forwarding where it uses the label swapping rather than the layer 3 complex lookups in a routing table. Implementing MPLS, alone creates an end to end path with bandwidth reservations which guarantees the availability of resources to carry traffic of volume less than or equal to the reserved bandwidth, but MPLS is not aware of the DiffServ classes which considered as a disadvantage. This research project demonstrated the usefulness of combining DiffServ and MPLS in voice-enabled network to enhance voice quality by reducing end to end delay, jitter, and packet loss and proposed a method for analyzing voice applications’ requirements based in DiffServ-aware MPLS network

Improving Prediction of Wireline Data Using Artificial Neural Network

This paper is dedicated to investigate the capabilities of artificial neural network (ANN) to improve prediction of petrophysical properties. Furthermore, this project is intended to test capability of network to predict the logging tools readings based on other tools readings. For petrophysical data prediction, it will be limited to predicting values of porosity by comparing predicted values from different models and values obtained from core data. Data obtained for core is considered to be the most accurate representation of petrophysical data. Hence, it is used as a reference data for testing capabilities of the model and training ANN networks

The Behavior and Choices of Serial Bidders in M&A Transactions: A Prospect Theory Approach

This paper investigates the impact of previous losses incurred by U.S serial bidders on their M&A strategic choices and premiums paid to acquire targets. The Hubris and Overconfidence theories suggest that managers tend to overpay as a result of exaggerating their ability to extract value and manage post-acquisition integration process between the acquiring firm and its target. Managerial overconfidence, which is signaled by conducting several acquisitions within a short time period or by other manager-specific investment attributes, has been shown to contribute to increasing premiums in M&A transactions and subsequent poor post-acquisition performance. Experimental findings in the area of psychology over the past three decades introduced the notion that economic agents experience utility resulting from changes in wealth (gains and losses) relative to a reference point rather than the level of total wealth and that losses loom larger than gains. The Prospect theory (Kahneman & Tversky, 1979) suggests that decision makers tend to be more aggressive (risk taking) after a loss in order to recover their losses and more risk averse after gains. The Quasi-Hedonic hypothesis (Thaler & Johnson, 1990) indicates that decision makers will become more risk taking after repeated gains ( House Money Effect ) but tend to be more risk averse after losses to avoid further pain. However, decision makers tend to be more risk taking after losses if there is a chance for breaking even. Using a sample of 16,582 M&A transactions by 3,512 U.S public bidders involved in at least two acquisition attempts over the 1990-2005 period, this study introduces several loss proxies based on corporate, market, industry and managerial compensation factors. Several empirical tests are conducted in this study to control for concurrent decisions taken by managers, endogeneity effects in explaining premiums, alternate model specifications, industry factors, time period effects as well as robustness for managerial overconfidence and entrenchment. The results are consistent across all sub-periods, however, the significance of M&A success history variables diminish over the 2001-2005 period. I present evidence that bidders suffering from earlier losses in terms of market, industry and compensation factors tend to be more aggressive in their target choices (i.e. choosing private and/or unrelated targets) and tend to overpay. Corporate loss events/shocks, such as failure to conclude an earlier merger deal, tend to motivate managers to make safer bets in terms of choosing public targets operating in related industries, however, still tend to overpay for targets. As the level of stock ownership of the bidder\u27s management/executive team increases, managers tend to respond to corporate failure events/shocks in a similar fashion as other loss proxies. The results presented are generally robust to overconfidence, insider ownership, sub-periods and industry wide factors. The results are also robust to the compensation structure of the management team and target-bidder relative size. In addition, the results presented in this study support the agency theory implications in regards to the bidder\u27s target choices (i.e., related/unrelated and private/public targets) and the market-driven/mispricing theory in regards to partially explaining premiums paid by bidders to acquire their prospective targets. The results presented provide support to the prospect theory propositions that losses experienced by economic agents induce an aggressive or risk taking behavior in subsequent bets by pursuing non-public and/or unrelated targets and offering higher premiums

Praćenje akcesornih spolnih žlijezda i testisa u ovnova pasmine barki pomoću Dopplera i ultrazvuka u B modu tijekom rasplodne sezone

The aim of this study was to perform ultrasonographic imaging of the testes and accessory sex glands in adult Barki rams during the breeding season. The impact of testosterone on the Doppler indices of accessory sex glands was also investigated. Scrotal contents, pelvic urethra and accessory sex glands of twelve mature Barki rams were scanned with multiple imaging of B-mode and colour Doppler ultrasonography. Serum concentrations of testosterone, FSH and LH were determined. The results revealed that the breeding season changed the echogenicity of testicular parenchyma, spermatic cord, epididymal tail, glans penis and echotexture of accessory sex glands. Serum testosterone was 7.27±0.37 ng/mL, FSH was 6.46±0.2 and LH was 5.6±0.28 m IU/mL. The pulsatility index (PI) for the supra-testicular artery (STA), marginal artery (MA) of the testes and epididymal tail was 1.01±0.07, 0.58±0.04 and 0.5±0.04. The resistive index (RI) for the same structures was 0.6±0.04, 0.33±0.04 and 0.3±0.03, respectively. Importantly, testosterone downregulated PI and RI of the ampulla, vesicular gland, prostate gland and bulbourethral gland. In conclusion, the breeding season changed the echogenicity of reproductive organs and accessory genital glands of rams, and testosterone regulated the hemodynamic parameters of the accessory sex glands.Ovo je istraživanje provedeno radi uspostavljanja normalnog ultrazvučnog (UZV) snimanja testisa i akcesornih spolnih žlijezda u odraslih ovnova pasmine barki tijekom rasplodne sezone. Osim toga, istraživan je i utjecaj testosterona na akcesorne spolne žlijezde temeljem uporabe Dopplera. Višestrukim snimanjem u B-modu i ultrazvučnim kolor Dopplerom pretraživan je sadržaj skrotuma, zdječna uretra te akcesorne spolne žlijezde u 12 odraslih ovnova pasmine barki. Određivane su serumske koncentracije testosterona, FSH i LH. Dobiveni su rezultati pokazali da u rasplodnoj sezoni dolazi do promjena u ehogenosti parenhima testisa, sjemenskog užeta, repa epididimisa, glansa penisa i ehoteksture akcesornih spolnih žlijezda. Razina serumskog testosterona iznosila je 7,27±0,37 ng/mL, FSH 6,46±0,2, a LH 5,6±0,28 m IU/mL. Pulzirajući indeksi (PI) supra arterije testisa (SAT), periferne arterije (PA) testisa i repa epididimisa bili su 1,01±0,07, 0,58±0,04, odnosno 0,5±0,04. Istovremeno, indeksi rezistentnosti (RI) gornjih kriterija su bili 0,6±0,04, 0,33±0,04, odnosno 0,3±0,03. Važno je spomenuti da je testosteron snižavao PI i RI ampule (a), vezikularne žlijezde, prostate i bulbouretralne žlijezde. Zaključno, rasplodna je sezona utjecala na promjene ehogenosti reproduktivnih organa i akcesornih spolnih žlijezda u ovnova. Nadalje, testosteron je regulirao hemodinamične pokazatelje akcesornih spolnih žlijezda tijekom rasplodne sezone u ovnova