A Study On The Effect Of Hydrophobically Modified Cationic Acrylamide Copolymers On Flocculation Properties Of Kaolin Suspension

A series of hydrophobically modified cationic polyacrylamides were synthesized via free radical solution copolymerization using ammonium persulphate/sodium hydrogen sulphite as the redox initiator.Satu siri kationik poliakrilamida hidrofobik terubah telah disintesis melalui larutan kopolimerasi radikal bebas dengan menggunakan ammonium persulfat/natrium hidrogen sulfit sebagai permula

Preparation, Characterization And Application Of Magnesium Salt-Polyacrylamide Hybrid Materials In Dye Wastewater Treatment

Magnesium salt-polyacrylamide hybrid materials were prepared, characterized and applied for reactive dye wastewater treatment. Polyacrylamide was prepared from acrylamide monomer through redox polymerization. The fundamental aspects of polyacrylamide redox polymerization were studied through investigation of mechanism, kinetics, thermodynamics and in situ rheological properties of the redox polymerization process. The redox polymerization of polyacrylamide was optimized through design of experiment. The physicochemical properties of the polyacrylamide were investigated in terms of chemical structure, molecular weight distribution as well as viscosity in aqueous solution. The yield of the optimal redox polymerization of polyacrylamide was 96.89% with molecular weight of 1.66 x 106 Da. Magnesium salt-polyacrylamide hybrid materials were prepared through physical blending of magnesium chloride and magnesium hydroxide with polyacrylamide in aqueous solution to form magnesium chloride-polyacrylamide (MCPAM) and magnesium hydroxide-polyacrylamide (MHPAM) hybrid materials, respectively

Primary Treatment of Dye Wastewater Using Aloe Vera-aided Aluminium and Magnesium Hybrid Coagulants

AbstractHybrid coagulants, aluminium sulphate-Aloe vera (ALAV) and magnesium sulphate-Aloe vera (MGAV) were prepared for the primary treatment of methylene blue (MB) dye wastewater treatment through coagulation-flocculation process. The effects of the independent factors and their interaction on the dye removal (%) were determined using two independent factors, i.e. pH and dosage based on 22 full factorial design. All the independent factors and their interaction were significant in removing dye. The dye removal (%) for both ALAV and MGAV were then optimized through central composite design. ALAV was able to remove 50–55% of dye while MGAV was able to remove 60-70% of dye. Therefore, MGAV was proven to be a more effective hybrid coagulant in removing dye

Streamlining non‐governmental organizations' programs towards achieving the sustainable development goals: A conceptual framework

After the launching of sustainable development goals (SDGs), nongovernmental organizations (NGOs) are identified as prominent players in localizing the SDGs. This has drawn attention of the research communities to shift from single‐sector approach to cross‐sectors approach in achieving the SDGs. However, the different capacity of NGOs is defined by the gaps of institutional factors and different approaches contributing to uncertain impacts that cannot be measured persistently. This limitation has caused many NGOs to choose in maintaining single‐sector approach that has been practiced in the millennium development goals previously. Subsequently, this may result to the lack of SDGs output exchange from the NGOs. Therefore, this paper proposes a conceptual framework to streamline NGOs' programs towards achieving the SDGs in two mechanisms, namely, cross‐sectors partnerships and broadening social value. Cross‐sectors partnerships are developed crossing around the institutional sectors of society as one central partnering process to organize and respond to common issues and concerns in SDGs. Broadening social value is one form of NGO's mechanisms to raise a social interest crossing into many sectors in the role of shifting single‐sector approach to cross‐sectors approach. This conceptual framework provides a basis for NGOs to plan their programs based on their capability and capacity in achieving the SDGs' target

Pencirian sifat kimia bahan tanah pada cerun gagal di sepanjang jalan Ranau-Tambunan, Sabah, Malaysia

Kawasan kajian yang terletak di kawasan pergunungan pantai barat Sabah sering dikaitkan dengan kejadian tanah runtuh dan kegagalan cerun. Secara geologi, kawasan di sepanjang jalan raya Ranau-Tambunan (RTM) terdiri daripada cerun potongan batuan sedimen arenit daripada Formasi Crocker dan metasedimen argilit daripada Formasi Trusmadi yang telah terluluhawa serta beberapa bahagian yang terdiri daripada endapan Aluvium Kuartener. Pencirian sifat kimia ke atas bahan cerun tanah yang gagal di kawasan tropika, terutama sekali di kawasan kajian jarang dilakukan. Pencirian ini adalah penting kerana bukan ciri fizikal bahan cerun sahaja yang mempengaruhi kejadian tanah runtuh. Oleh itu, kajian ini memberi perhatian utama kepada pencirian sifat kimia dan mineralogi lempung telah dilakukan ke atas cerun-cerun yang gagal di kawasan kajian. Bagi mencapai objektif kajian ini, sebanyak 12 sampel tanah cerun gagal yang terdiri daripada luluhawa gred VI diuji. Analisis inventori cerun gagal menunjukkan terdapat 10 kegagalan cerun tanah (T) dan 8 kegagalan jenis khas (TB) dengan 3 kegagalan cerun dikelaskan berisi padu besar (> 500 m3), 7 cerun berisi padu sederhana (50 - 500 m3) dan 2 kegagalan cerun berisi padu kecil (10 – 50 m3). Analisis kimia menunjukkan kandungan organik tanah (BOT) yang rendah hingga sederhana daripada 3.75%-7.23%, pH tanah dikelaskan sebagai berasid amat tinggi hingga beralkali rendah. Analisis XRD menunjukkan komposisi mineral lempung utama terdiri daripada kaolinit dan ilit dan beberapa mineral lain seperti montmorilonit, haloisit, dickit dan vermikulit. Komposisi mineral bukan lempung utama terdiri daripada kuarza dan muskovit. Hasil kajian menunjukkan wujud perkaitan signifikan antara sifat kimia dan mineralogi tanah daripada segi pertukaran unsur kimia, hubungan air liang dan kekuatan ikatan butiran tanah dalam pembentukan mineral lempung yang menggalakkan berlakunya kegagalan cerun. Oleh itu, pembinaan dan pengurusan kerja-kerja potongan cerun bukan sahaja mengambil kira aspek sifat fizikal dan kejuruteraan tanah malah sifat kimia tanah juga amat penting terutamanya yang melibatkan batuan yang terluluhawa supaya sebarang kegagalan yang melibatkan cerun potongan dapat ditangani sewajarnya

Public benefit and risk perceptions of nanotechnology development: Psychological and sociological aspects

Nanotechnology enables the development of new and improved products. However, the public is also concerned about uncertain risks associated with nanotechnology-enabled products. To address this concern, the study aims to expand the understanding about public benefit and risk perceptions as a basis for the effective formulation of policy that addresses public interests. The study investigates public benefit and risk perceptions of nanotechnology development from the psychological and sociological aspects through a questionnaire survey conducted on Klang Valley, Malaysia. Analysis of variance (ANOVA) illustrates that demographics indeed influences public benefit and risk perceptions of nanotechnology development. However, public knowledge about nanotechnology exerts no effect on public benefit and risk perceptions of nanotechnology development based on independent t- tests. Simple linear regression reveals that the lack of public trust in government increases risk perception. Public attitude perceives nanotechnology to be more beneficial than risky, thus influencing benefit perception rather than risk perception. Public lifestyle, such as culture, religious beliefs and social group influence benefit perception but not risk perception. Result is expected to deliver better communication of benefit and risk of nanotechnology to the public as well as ensure an ethical policy regarding nanotechnology development

Penyingkiran ammonia dan logam berat daripada air sisa industri automotif menggunakan pasir terubah suai secara kimia

Keberkesanan rawatan air sisa industri automotif ditentukan dengan menggunakan kaedah penjerapan turus. Peratusan penyingkiran ammonia dan logam berat terpilih telah dikaji menggunakan pasir biasa dan pasir terubah suai secara kimia sebagai bahan penjerap. Dua model matematik iaitu Model Thomas serta Model Yoon-Nelson telah digunakan untuk menentukan kapasiti penjerapan maksimum ammonia. Peratusan penyingkiran ammonia menunjukkan pasir terubah suai secara kimia mencatatkan julat peratusan penyingkiran yang lebih tinggi iaitu 43.68% hingga 96.55% berbanding pasir biasa yang mencatatkan julat 0% hingga 89.66%. Logam berat zink, mangan, kromium, kuprum, arsenik, nikel, kobalt dan ferum mencatatkan peratusan penyingkiran antara 93% hingga 100% apabila menggunakan pasir terubah suai secara kimia manakala pasir biasa mencatatkan julat peratusan penyingkiran daripada 0.8% hingga 100%. Keputusan analisis menggunakan Model Thomas menunjukkan kapasiti penjerapan maksimum, qo ammonia menggunakan pasir terubah suai secara kimia (8.80 mg/g) adalah empat kali lebih tinggi daripada pasir biasa (2.57 mg/g) manakala masa bolos, t0.5 bahan penjerap yang ditentukan menggunakan Model Yoon dan Nelson mencatatkan masa tertinggi bagi pasir terubah suai secara kimia iaitu 30.18 min berbanding 9.57 min bagi pasir biasa. Kajian ini menunjukkan peratusan penyingkiran dan kapasiti penjerapan ammonia dan logam berat terpilih iaitu zink, mangan, kuprum, arsenik, nikel, kobalt dan ferum lebih tinggi bagi turus pasir terubah suai secara kimia berbanding pasir biasa

Psychological and sociological perspectives for good governance of sustainable nanotechnology development in Malaysia

Nanotechnology is developed to improve public well-being, stimulate economic growth, and provide environmental solutions, which are essential for sustainable development. However, the uncertain risks of nanotechnology may destroy public confidence and impede nanotechnology development from facilitating sustainable development. Thus, public perception is a critical component to understand public acceptance of nanotechnology and for nanotechnology development to be well governed. Good governance of nanotechnology is vital to ensure the benefits are distributed equitably while protecting the public from the risks. Hence, this study was based on psychological and sociological approaches with intervention from moderators, that is, media coverage, technology and economic development, benefit and risk of nanoapplications, and benefit and risk information. A survey was conducted in Malaysia to determine the effects of moderators’ influence on public perceptions. The study found, based on a psychological and sociological approach, that the moderating effects of moderators influenced public perception in a manner that increased or decreased the benefit and risk perception of nanotechnology. The results later serve as an input for recommending good governance strategies for applying nanotechnology to sustainable development

Assessment of ultimate bearing capacity based on the Hoek-Brown failure criterion

The ultimate bearing capacity is an essential requirement in design quantification for shallow foundations especially for structures built on large rock masses. In many engineering projects, structures built on foundation of heavily jointed rock masses may face issues such as instability and sudden catastrophic rock slope failure. Determination of the ultimate bearing capacity (Qult) of foundations resting on rock mass has traditionally been determined by employing several strength criterions. One of the accepted and widely implemented methods is to use the Hoek-Brown failure criterion 2002, where the required parameters are determined from a rock mass classification system, Geological Strength Index (GSI). This paper defines an assessment for ultimate bearing capacity (Qult) based on the Hoek-Brown failure criterion 2002 for a granitic rock slope beneath a 20 m diameter concrete water tank at Bandar Mahkota Cheras, Kajang, Selangor. Based on the Hoek-Brown failure criterion 2002, the ultimate bearing capacity (Qult) of rock mass was 7.91 MPa. The actual stress acting on the rock mass was 0.32 MPa. The assessment showed that the rock mass is safe since the ultimate bearing capacity (Qult) is 24.7 times higher than the actual stress acting on the rock mass

Peak friction angle estimation from joint roughness coefficient of discontinuities of limestone in Peninsular Malaysia

The peak friction angle (φpeak) roughness of discontinuity surfaces is a value that is fundamental to the understanding of shear strength of geological discontinuities, considering its importance in determining the mechanical properties of the discontinuity surface. It is however, both time and cost demanding to determine the peak friction angle as it requires an extensive series of laboratory tests. This paper presents an approach in the form of an experimentally determined polynomial equation to estimate peak friction angle of limestone discontinuity surfaces by measuring the Joint Roughness Coefficient (JRC) values in a field survey study, and applying the fore mentioned empirical correlation. A total of 1967 tilt tests and JRC measurements were conducted in the laboratory to determine the peak friction angles of rough limestone discontinuity surfaces. The experimental results were analyzed and correlated to establish a polynomial equation of φpeak = -0.0635JRC2 + 3.95JRC + 25.2 with coefficient of determination (R2) of 0.99. The laboratory results were also compared with theoretical results calculated from Barton’s linear equation. The results shown that estimation of peak friction angles were more accurate using the newly proposed polynomial equation since the percentage differences between measured and calculated peak friction angles is less than 6% compared to estimation from Barton’s linear equation where the percentage of differences is less than 11%. The proposed correlation offers a practical method for estimation of peak friction angles of discontinuity surfaces of limestone from measurement of JRC in the field