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Home > Enzymatic and Bacterial Modifications of Natural Biofibres for Synthesis of Biocomposites

Enzymatic and Bacterial Modifications of Natural Biofibres for Synthesis of Biocomposites

Thesis Info

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Author

Zanib Ahmed

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2016

Thesis Completion Status

Completed

Subject

Biochemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9601/1/Zanib_Ahmed_Biochemistry_HSR_UAF_2016_10.01.2017.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726072364

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Environmental concerns have been motivating research in the field of biodegradable materials, especially those from biological sources. Plant fibres are hydrophilic in nature due to interaction with the hydroxyl group of their components and water molecules which results in poor adhesion of these biopolymers to the reinforcing materials due to low compatibility with the hydrophobic polymer matrices that result in inefficient transfer of stress from the matrix to the reinforcing material. Environment friendly methods such as plasma treatment, treatments using fungi, enzymes and bacteria, can be used for the surface modification of plant fibers. In this context, a series of bio-composites e.g. polyvinyl alcohol (PVA) with lignocellulosic substrate (native and delignified) based biocomposites and PVA along with bacterial cellulose modified substrate based biocomposites were successfully synthesized by introducing maleic anhydride as compatibilizer and glycerol as a plasticizer. The lignocellulosic materials (sugarcane bagasse, wheat straw and rice straw) were treated enzymatically and the best delignified substrate was further modified by depositing Acetbacter xylinum. Blends were compression molded and the resulting bio-composites were removed from their respective casting surfaces under ambient environment and characterized using different analytical and imaging techniques. Dynamic mechanical analysis (DMA) was performed to study the mechanical properties of the composites. The structural changes in the composites were analyzed using Fourier transform infra-red spectroscopy (FT-IR), the morphological properties of the bocomposites were studied using Scanning electron microscopy (SEM) and the water absorption behavior of the biocomposites were also determined. The tensile strength, elongation at break point, and Young’s modulus values of the bio-composites reached very high levels in comparison to the composites prepared with pure PVA and pure native straw that were too fragile to be measured for any of the above mentioned characteristics. Morphological analysis of the newly developed biocomposites surfaces through SEM showed a uniform distribution of the PVA and reinforcing substrate. Also there was a marked improvement in the water absorption content of the biocomposite synthesized from 1:3 ratio of wheat straw and PVA. The development of biocomposites by using lignocellulosic biofibres as reinforcement materials will form the basis for the potential use of these biocomposites in various industries.
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نسل در نسل دشمنی

جائیداد کا تنازعہ نسل درنسل دشمنی

                 ناول نگار نے کہانی میں تین بھائیوں کا ذکر کیا ہے جو کہ ضلع خانیوال کے گاؤں ٹبہ والی میں رہتے تھے۔صادق بخش،الٰہ بخش،احمد بخش تینوں بھائیوں کے پاس زمین جائیداد بتائی گئی ہے احمد بخش جو کہ ان سب سے بڑا ہے اس کا ایک بیٹا ہے۔طلال احمد،دوسرے بھائی کی ایک بیٹی ہے بیٹی کی پیدائش پر بیوی کا انتقال ہو گیا اور تیسرے بھائی کی دو بیویاں ہیں مگر اولاد کوئی نہیں۔ان تینوں بھائیوں کا باپ جنگ عظیم دوم میں انگریزوں کے خلاف جنگ کرتا ہوا اپنے ایک بازو سے ہاتھ دھو بیٹھا اس صورت میں اسے حکومت کی طرف سے زمین الاٹ کی گئی، کچھ بعد میں یہ بھائی اپنے دماغ سے اضافہ کرتے گئے۔تینوں بظاہر بہت اچھے بھائی تھے۔ مگر طلال احمد جو کہ دل میں بغض رکھتا تھا، وہ اور اس کا باپ احمد بخش تین ہزار ایکڑ کے امورخود سے ہی دیکھتے تھے۔سب کام بہت خوش اسلوبی سے ہورہے تھے۔تینوں بھائیوں میں بگاڑ تب پیدا ہواجب دوسرا بھائی اپنی زندگی میں ہی اپنے حصے کی زمین اپنی بیویوں کے نام کردینا چاہتا تھا۔ناطق نے بھائیوں کے پیار میں بھی بتایا ہے کہ خون کے رشتے ،سگے بھائی بھی کس طرح جائیداد کے لالچ میں ایک دوسرے کے خون کے پیاسے ہو جاتے ہیں۔صادق بخش ہمیشہ سے چاہتا تھا اور اس سلسلے میں اپنے بڑے بھائی احمد بخش کو بہت بار کہہ چکاتھاکہ وہ اپنا حصہ اپنی بیویوں کے نام کرنا چاہتا ہے اور احمد بخش ہمیشہ ٹال مٹول سے کام لیتا تھا۔دونوں میں بہت تکرار ہوگئی اور بات طے پائی کہ وہ اس سال  کپاس کی کاشت پر رقم دونوں بیویوں میں تقسیم کردے گا۔اس تکرار کی وجہ سے اب بھائی ساتھ میں کم بیٹھتے تھے۔مگر احمد بخش نے اپنا...

حدیثِ لولاک کا تحقیقی و تجزیاتی مطالعہ A Research Review of the Hadith e Lawlāk

The importance and authenticity of the hadiths of the Prophet (PBUH) in the Muhammadan Ummah is an undisputed fact. A large number of Muḥaddithīn and imams spent their lives in collecting and editing the hadiths of the Prophet (PBUH) and compiled a collection of hadiths. These hadiths were classified according to their health and weakness. Due to the efforts of the imams, there are hadiths narrated from the Messenger of Allah on all sciences and knowledge and issues and rulings. Among them are Hadith Qudsī, Ma‘rūf, Mawkūf, Maktū‘, Saḥiḥ, Ḥasan Za‘īf and all other types of Hadith. The same Hadith e Qudsīyyah also includes a Hadith Lawlāk "لولاک" refers to those hadiths in which the Prophet ﷺ has been described as the cause of the creation of the universe and the origin of the universe. That is the hadith in which Allah Almighty has related the Prophet (PBUH) as the reason for creating the universe and its beings. However, the words of "Hadith e Lawlāk" The authenticity of the hadith has been made a subject of discussion. Some imams have declared this hadith to be weak and some have also said that it is valid. However, a large number of scholars have agreed on the authenticity of this hadith and the hadith has been declared correct in terms of meaning and has been recorded in the books of hadith, biographies and interpretations and other subject books. In the article under review, the sayings of Imams on the health and weakness of Hadith Lawlāk have been presented and research analysis of the said Hadith has been done through simulation and rational arguments.

Analyzing Effects of Air Decks on Fragmentation and Economics of Bench Blasting

The airdeck blasting technique has been used in the past to reduce the explosive charge and to improve the rock fragmentation. However, the mining and construction industry of Pakistan has always been reluctant to use airdecks in their blasting operations. This is due to the fact that researchers and practitioners have a divided opinion about the efficiency of this technique. In fact, several attempts in the past have been made to find out the best position and optimum length of airdeck for better fragmentation. Since, in the previous studies most of experiments were carried out under varying geological conditions, it was very difficult to suggest the best possible location and optimum length for airdeck in an explosive column for better fragmentation. In order to find out the best position of airdeck in explosive column that yields better fragmentation, it was necessary to carry out all experiments on homogeneous material and in controlled geological conditions. So that research findings indicate a correlation between the concerned variables only and a benchmark research could be established. Therefore, special homogeneous concrete blocks were designed for this research. These concrete blocks eliminated the heterogeneity and anisotropy of rock material, such as the fractures, folds, faults and joints of rock. Such factors have been found to play a very crucial role in the size of debris produced from the blasted rock material. This research will address two fundamental questions; the technical and the economic efficiency of the airdeck blasting technique. All the blasting experiments in this study were carried out in two phases. In the first phase, a series of small scale experiments was conducted using homogeneous concrete blocks. In order to find out the proper position and optimized length of the airdeck, it was ensured that the concrete blocks had almost the same uniaxial compressive strength. More than 40 tests with concrete blocks were performed for this purpose. The evaluation of fragmentation by sieve analysis revealed that an improved rock fragmentation was achieved when the airdeck was placed in the center of the explosive column. Moreover, it was also observed that the mean blasted rock fragment size increased with the increase in airdeck size and the best results were achieved at 20% airdeck length. In the second phase of this research, the results of experimentation on concrete blocks were validated on relatively homogeneous limestone at two cement quarries: DG. Cement Chakwal and Askari Cement Nizampur. Several test blasts were carried out with full column charge without airdeck and with 20% airdeck length placed at middle of explosive column. The analysis of fragmentation for the benches after blast was done using Split Desktop software. Subsequently it was deciphered that at both the cement quarries, better fragmentation was achieved by placing airdeck at middle of explosive column as compared to when there was no airdeck in the full column charge. This research work also includes the use of multiple airdeck lengths placed at middle position of explosive column for the limestone quarry and the results indicate improved fragmentation. The results of this research work clearly indicate that airdeck, when placed at middle position of an explosive column produce more uniform blasted rock size distribution compared to that at other positions. Moreover, the optimum length of airdeck is 20% of the total length of explosive column and it improves environmental factors like fly rocks, air blast, ground vibrations etc. The underlying reason behind this is that the airdeck at middle position results in multiple impacts of shock wave that leads to an efficient transfer of explosive energy in the surrounding rocks. Economic analysis of explosive cost at both quarries was also conducted in this study. From economic analysis at DG Cement Chakwal, it was observed that up to 2.5 rupees per tonne of explosive cost could be saved by adopting 20% mid-airdeck length in the explosive column as compared to the cost incurred for conventional blasting techniques. By using above mentioned technique, saving per tonne can be increased by 16% and rupees 750,000 can be saved at the DG. Cement quarry monthly assuring an annual saving of rupees 9 million. Similarly, the economic analysis conducted from the results of blasting at Askari Cement Nizampur, it was observed that 2.6 rupees per tonne of explosive cost can be saved by adopting 20% mid-airdeck length in the explosive column to enhance the fragments as compared to the cost incurred for conventional blasting techniques. Therefore, using 20% mid-airdeck length in explosive column, saving per tonne can be increased by 10.4% and rupees 468,000 can be saved at the Askari Cement quarry monthly assuring an annual saving of 5.6 million rupees. By using 20% airdeck lengths in explosive column, Rs. 44.33 million can be saved annually for explosive used by Punjab, province of Pakistan. This amount can be calculated for other provinces of the Pakistan as well. There are many other minerals is Pakistan which require blasting for their production. If we could use the improved airdeck blasting technique for the production of those minerals, billions of rupees can be saved annually. Moreover, by incorporating the effect of even fragmentation from blasting on downstream processes like crushing, milling etc. millions of rupees can be saved. It is anticipated that this study will provide answers and guide lines to researchers and practitioners who were confused about best location and optimum length of airdeck to be used in explosive column for achieving the optimum fragmentation.