766 research outputs found

    Developmental changes in the histological structure of the testes, and testosterone profiles in male guinea fowls (Numida meleagris)

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    Owing to the paucity of information on the reproductive biology of guinea fowls, a study involving a total of 66 males was conducted, and documented the developmental changes in histological structure of the testes of guinea cocks from hatching until adulthood. Changes in testosterone synthesis during sexual development were also determined. Age-related changes were analysed using univariate analysis for completely randomised design and means separated using Tukey's test/Kruskal-Wallis test and medians separated by Mann-Whitney U test. Total germ cell population per testis and testicular histological morphometric parameters increased significantly (p < 0.0001) from 12 weeks of age (WOA), and stabilized between 20 and 24 WOA. Peripheral testosterone concentrations increased gradually from 4 WOA, and peaked at 20 WOA. Correlations among all the testicular morphometric parameters were positive and highly significant (p < 0.01). Similarly, significant (p < 0.05) positive correlations existed between testicular weight and testicular sperm production, tubular diameter, Sertoli cell population, tubular length and peripheral testosterone concentration. Testicular sperm production was positively correlated with meiotic index (p < 0.01) and round spermatids population (p < 0.05). The correlations between peripheral testosterone concentrations, tubular diameter and Sertoli efficiency were also significant (p < 0.05) and positive. Testicular morphometric parameters stabilized between 20 and 24 WOA, while peripheral testosterone concentrations showed two patterns of secretion, initial and final phases of increasing and decreasing testosterone secretions, respectively, and may be implicated in the development of histological structures of the testes and spermatogenesis. [Abstract copyright: Copyright © 2017 Elsevier Inc. All rights reserved.

    The structural approach to city image (Al-Madinah Al-Munawarah)

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    Today there are huge and radical changes taking place in the development of almost all the cities of the Muslim world, among them the city of Al- Madinah Al- Munawarah. These have brought profound changes in ways of life, urban structure and styles of architecture which have permeated and transformed the very social and physical fabric of the cities and are destroying the quality of the urban environment and Muslim way of life. The Muslim city is in danger of becoming a mere copy of the worst elements of many Western cities: ugliness, noise, air pollution, a frenetic way of life and all the associated social problems. Meanwhile it is felt fundamental to approach Islamic civilisation not as a mere object of investigation, with the Muslim city as its museum of historical heritage, but as a living reality, a faith and an inspiration to milliards of people in the world of Islam who do not separate their ethical values and their cultural identity from their demands for social welfare, justice and a humane quality of life within the modern process of economic development. Since we live in the world of the mind, it follows that the problems can be seen as a battle for the mind. In this realm of persuasion and stimulation it is the image which assumes the key role and it is the image makers - the authors, controllers and artists, among them the built environment professionals - who hold a special responsibility. Furthermore it is the reasons and processes underlying the formation of particular interests and images that take on special significance. This is critical if one tries to solve the problems of the formation and development of the symbolic patterns in a historical city such as the city of Al- Madinah, which is known as the City of the Prophet Muhammad (peace be upon him). The author aims to propound a comprehensive study of the patterns of tradition and historic events of the Prophet's time which inspired and generated the form of the city of Al- Madinah. The study focuses on the preservation of the deep images embedded in people's perception of the city in order to project them to sustain its form in the future. Therefore, the author has in mind the objective of conserving Islamic architectural heritage in general, and the necessity of impressing, on the consciousness of the powers that be, the urgency of preserving the heritage of the city of Al- Madinah before it in particular is destroyed. The City of the Prophet must be considered as being on no account expendable, regardless of the gains made in replacing the old by the new. Finally the present study forms a sequel to the findings extracted from literature and from the case study, as related to the Islamic Legal System. Common to all these fields is the view that architecture represents a means to give man an existential foothold, similar to the view of phenomenological approaches. The author's primary aim is therefore to investigate the psychic implications of architecture rather than its practical side, although he certainly admits that there exists an interrelationship between the two aspects. In reviewing the literature, the "structural" dimension is discussed as part of a comprehensive system in transformation. At the same time, the thesis stresses that the environment influences human beings, implying that the purpose of architecture transcends the definition given by structuralism. A discussion of perception and image has been therefore included emphasising that man cannot gain a foothold through scientific understanding alone. He needs symbols, that is, works of art which represent life- situations. It is one of the basic needs of man to experience his life -situations as meaningful, and the purpose of the work of art is to reflect meanings. The concept of "meaning" is also a strong theme throughout thesis

    Potential Effects on Large Mara Construction Projects Due To Construction Delay

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    The construction industry continues to be the driving force in the growth of the nation’s socio economic development. One of the major issues in large construction industry is its frequent delay where this delay decelerates the multiplier effects to the economy. This paper presents the study of a survey on significant cause of delay and its effects in large MARA (Majlis Amanah Rakyat) construction project in the views of project management consultants (PMC). Respondents of this survey were personnel that work as PMC ranging from the executives, managerial and supporting groups. The result revealed that the five most significant delay causes as seen by PMC were cash flow and financial difficulties faced by contractors, contractor’s poor site management, inadequate contractor experience, shortage of site workers and ineffective planning and scheduling by contractors and its three most significant effects were time overrun, cost overrun and arbitration. Hopefully, the findings of this study will at least shade some lights to the problems faced by Malaysia construction industry particularly MARA large construction project and effort can be taken to improve it

    Control Chart Pattern Recognition Using Small Window Size for Identifying Bivariate Process Mean Shifts

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    There are many traits in the manufacturing technology to assure the quality of products. One of the current practices aims for monitoring the in-process quality of small-lot production using Statistical Process Control (SPC), which requires small samples or small window sizes. In this study, the recognition performance of bivariate SPC pattern recognition scheme was investigated when dealing with small window sizes (less than 24). The framework of the scheme was constructed using an artificial neural network recognizer. The simulated SPC samples in different window sizes (8 ~ 24) and different change points (fixed and varies) were generated to study the recognition performance of the scheme based on mean square error (MSE) and classification accuracy (CA) measures. Two main findings have been suggested: (i) the scheme was superior when recognizing shift patterns with various change points compared to the shift patterns with fixed change point, with lower MSE and higher CA results, (ii) the scheme was more difficult to recognize smaller window size patterns with increasing MSE and decreasing CA trends, since these patterns provided insufficient information of unnatural variation. The outcome of this study would be helpful for industrial practitioners towards applying SPC for small-lot-production. &nbsp

    Control Chart Pattern Recognition Using Small Window Size for Identifying Bivariate Process Mean Shifts

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    There are many traits in the manufacturing technology to assure the quality of products. One of the current practices aims for monitoring the in-process quality of small-lot production using Statistical Process Control (SPC), which requires small samples or small window sizes. In this study, the recognition performance of bivariate SPC pattern recognition scheme was investigated when dealing with small window sizes (less than 24). The framework of the scheme was constructed using an artificial neural network recognizer. The simulated SPC samples in different window sizes (8 ~ 24) and different change points (fixed and varies) were generated to study the recognition performance of the scheme based on mean square error (MSE) and classification accuracy (CA) measures. Two main findings have been suggested: (i) the scheme was superior when recognizing shift patterns with various change points compared to the shift patterns with fixed change point, with lower MSE and higher CA results, (ii) the scheme was more difficult to recognize smaller window size patterns with increasing MSE and decreasing CA trends, since these patterns provided insufficient information of unnatural variation. The outcome of this study would be helpful for industrial practitioners towards applying SPC for small-lot-production. &nbsp

    Identifying Unnatural Variation in Precision Rotational Part Manufacturing

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    In the manufacturing industry, it is well known that in-process variation is a major contributor to poor quality products. In order to fabricate a precise part, the source of unnatural variation (UV) needed to be properly identified, monitored and controlled while the process is running. In relation to this issue, this study aims to identify the error root causes of UV in bivariate process associated with statistical process control (SPC) chart patterns. In research methodology, in-process variation in manufacturing roller head component was discussed systematically based on real product of roller head, computer aided design (CAD) and statistical process control (SPC) chart patterns. Initially, the CAD software was used to model a precise rotational part, and to analyse the cause of UV. Then, the programming software was used to generate the artificial SPC data streams based on an established mathematical model. Data generation also involved linear correlation between two dependent variables (bivariate). The outcome of this study would be helpful for industrial practitioners as a database when applying SPC for monitoring bivariate process

    Kesan penambahan limonena terhadap mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air

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    Gambar rajah fasa pseudo-ternari sistem mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air diperoleh melalui pentitratan air pada nisbah surfaktan:kosurfaktan (Km) yang berbeza. Nisbah optimum bagi surfaktan/kosurfaktan adalah Km=2:1. Kesan penambahan limonena sebagai fasa minyak campuran terhadap sistem mikroemulsi diuji pada nisbah limonena:asid oleik (1:1, 2:1 dan 3:1). Penambahan limonena berupaya menghasilkan rantau mikroemulsi yang lebih besar sehingga 70%-80 % bt. air bagi kesemua nisbah limonena:asid oleik. Nisbah limonena:asid oleik (1:1) memberikan rantau mikroemulsi yang paling luas pada nisbah minyak:surfaktan/kosurfaktan (Minyak:S/KoS=1:9). Sifat isotropik mikroemulsi ditentukan dengan menggunakan mikroskopi cahaya polarasi. Mikroemulsi dibangunkan pada nisbah Km=2:1 dan Minyak:S/KoS (1:9) serta limonena:asid oleik (1:1). Kestabilan dan saiz partikel bagi sistem dikaji dan penambahan limonena didapati tidak merubah sifat serta mikro-struktur sistem mikroemulsi. Kajian konduktiviti elektrik dan kelikatan sistem menunjukkan pembentukan mikroemulsi jenis air-dalam-minyak (10% dan 20 % bt. air) dan dwiselanjar (30%-50 % bt. air). Kesemua sistem mempunyai potensi sebagai sistem penghantar bahan aktif dan menunjukkan kestabilan yang baik pada suhu 4, 25 dan 37°C dalam tempoh lebih daripada 6 bulan

    Compressive Strength and Water Permeability Performance of Micronised Biomass Silica Concrete

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    Concrete is a common material that is widely used in construction industry. Cement is the main material component for producing concrete but its production has lead into CO2 emission. This work presents a study on Micronised Biomass Silica (MBS) that can be used as pozzolan material which can enhance the quality of concrete. The material can be produced from a by-product of biomass agricultural waste but for this study rice husk has been used. From the chemical analysis, MBS has a chemical composition that is fulfill the standard requirement for becoming pozzolan material. The result of MBS concrete shows that the MBS material can enhance the performance of concrete by increasing the compressive strength development and reducing the water permeability. The drawback of MBS is the workability of fresh concrete but can be rectify by using superplasticizer. By replacing up to 12% of cement, MBS material gives the highest performance in term of strength and permeability of the concrete

    Prediction of Soil Anisotropic Stress-Strain Behaviour Incorporating Shear Strength Using Improvise Normalised Stress-Strain Method

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    Currently the soil anisotropic stress-strain behaviour can be predicted accurately at any effective stress using the Rotational Multiple Yield Surface Framework. This framework incorporates the developed of mobilised shear strength within the body of the soil mass whenever the soil is subjected to anisotropic compression. However the accuracy of the framework can be improvised since the failure axial strain is not unique but increases as the effective stress increases. This improved method s call normalised strain method. This method is applied to predict the stress-strain behaviour of granitic residual soil grade V from Kuala Kubu Baharu. The improve accuracy of this method will be presented in comparison with the conventional method
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