FRESH STATE AND MECHANICAL PROPERTIES OF ULTRA-LIGHTWEIGHT FOAMED CONCRETE INCORPORATING ALKALI TREATED BANANA FIBRE

For a Lightweight Foamed Concrete (LFC) to efficiently function as an energy-saving building material, its self-weight (density) should be reduced. However, the problem associated with a reduced density is a decline in strength. To improve the mechanical properties of LFC, this research attempts to integrate banana fibre into LFC composite with a focus on fresh and harden state properties. An Ultra-Lightweight Foamed Concrete (ULFC) with a density of 600 kg/m3 was produced with the inclusion of treated and untreated banana fibres. The volume fractions of banana fibre added into LFC were 0.00% (control specimen), 0.25%, 0.35%, 0.45% and 0.55%. In addition, an optimised batch mix of ULFC reinforced with 0.35% untreated banana fibre was produced. The batches were tested for rheological, physical, and mechanical properties. Findings reveal that the workability of ULFC composites decrease with increase in fibre addition. The compressive, flexural, and tensile strengths of the alkali-treated composites were higher than the untreated banana fibre composite. SEM micrograph reveals that defibrillation of bundle fibrils due to cleaning the surface amorphous hemicellulose, lignin and pectin of the alkali-treated fibre, leads to rough surfaces and increase surface area resulting in better interfacial adhesion of the fibre with cement matrix.

Heat transfer analysis on different pin fin types using Solid Works

A fin is an extended part of an object whose purpose is to raise the rate of heat transfer mainly by convection. The heat flow in any object depends on the surface area, temperature difference, and convection coefficient. As convection coefficient cannot vary after a certain limit and temperature difference depends on the process, the way to increase the rate of heat transfer is to increase surface area which was done by adding fins. In this study, steady-state thermal analysis is performed on different types of fins and fins of different heights by using Solid works simulation. Different materials of fins are also used to verify results as the rate of heat transfer is independent of material. Aluminum 6061 and Copper is used as material for rectangular and cylindrical pin fins. In comparison, rectangular pin fin has a high rate of heat transfer as compared to copper pin fin, and also the rate of heat transfer is directly proportional to the height of the fins irrespective of the profile.

Activated Bledug Kuwu’s Clay as Adsorbent Potential for Synthetic Dye Adsorption: Kinetic and Thermodynamic Studies

Bledug Kuwu is one of the geological phenomena as a mud volcano that occurs in Kuwu, Purwodadi, Grobogan, Central Java, Indonesia. The evaluation of Bledug Kuwu’s clay as one of the adsorbents for synthetic dyes has been carried out. The preparation of the adsorbent started with washing the clay with distilled water, followed by activation with a solution of hydrochloric acid (1 M) under mechanistic stirring for overnight. The C−H and O−H groups found on the clay adsorbent could attract methylene blue by dispersion forces and hydrogen bonding. Hydrocloric acid activation process for clay can increase surface area from 49 to 70 m2.g−1, meanwhile, reducing the average crystal size from 48.3 to 43.4 nm. The dye removal capacity increased from 34 to 40 mg.g−1 in corresponding to the increase of the temperature from 30 to 50 °C. The results showed that the equilibrium adsorption capacity of activated Bledug Kuwu’s clay reached 99% in an adsorption time of 20 min. The kinetic models of methylene blue adsorption onto BKC and ABKC adsorbents follow the pseudo-second order and the adsorption process is spontaneous with free energy (ΔG) as −23.519 kJ.mol−1. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Electrochemical Sandwich Assays for Biomarkers Incorporating Aptamers, Antibodies and Nanomaterials for Detection of Specific Protein Biomarkers

The development of sensitive and selective assays for protein biomarkers and other biological analytes is important for advancing the fields of clinical diagnostics and bioanalytical chemistry. The potential advantages of using aptamers in electrochemical sandwich assays are being increasingly recognized. These assays may include an aptamer as both capture and detection agent or a combination of an aptamer with a different partner such as an antibody, a lectin or a nanomaterial. The second binding partner in the sandwich structure is typically conjugated to a redox marker, a catalyst or an enzyme that can be used to generate the signal needed for electrochemical detection. Nanoparticles and other nanostructures can be used as the carriers for multiple molecules of the detection partner and thereby increase the signal. Nanostructured surfaces can be used to increase surface area and improve electron transfer. Sensitive electrochemical methods including impedance, differential and square-wave voltammetry and chronocoulometry have been used for electrochemical signal read-out. Impressive results have been achieved using electrochemical sandwich assays in terms of limit of detection and linear range for a growing range of analytes. The recent progress for this type of assay for proteins and other biomarkers is the subject of this review.

Braincase anatomy of the Paleocene crocodyliform Rhabdognathus revealed through high resolution computed tomography

Dyrosaurids were highly specialized, largely marine, relatives of living crocodylians, and one of the few archosaur lineages to survive the K-Pg extinction. Dyrosaurids lived during the Cretaceous to the Eocene and represent a unique combination of morphology and ecology not seen in living crocodylians. Little is known about their endocranial anatomy, leaving many questions about their neurosensory adaptations unaddressed. Recently, µCT (micro-computed tomography) scans were made of a well-preserved skull of Rhabdognathus, a Paleocene dyrosaurid from Mali. This marks the first time the braincase and neurosensory features of a dyrosaurid have been examined using CT. We focus our attention to three specific internal structures: the cranial endocast; the inner ear; and the paratympanic sinuses. The cranial endocast of Rhabdognathus revealed novel features including a unique conformation of its paratympanic system, a prominent dorsal venous system that communicates with the external skull table, extremely enlarged tympanic vestibules that meet at the midline of the endocranium, a prominent spherical cerebrum, and elongate olfactory tracts accounting for half the total endocast length. The bizarre laterally facing lateral Eustachian foramen of dyrosaurids is now understood to be a complex fossa including both a ventrally directed lateral Eustachian foramen and a laterally directed foramen for the basioccipital diverticulum. A novel median pterygopharyngeal canal was discovered connecting the pharynx to the adductor chamber. These revelations require a reinterpretation of the associated external foramina visible on the posterior of the skull in dyrosaurids and potentially their close relatives the pholidosaurids. The olfactory tract terminates in an enlarged olfactory region possessing complex bony projections—a unique morphology perhaps serving to increase surface area for olfaction. The inner ear of Rhabdognathus exhibits characteristics seen in both Pelagosaurus and Gavialis. The vestibule is spherical, as in Gavialis, but is significantly expanded. The semicircular canals are enlarged but pyramidal in shape as in the thalattosuchian Pelagosaurus. The proportion of the cochlear length to total endosseous labyrinth height is roughly 0.5 in Rhabdognathus implying that the hearing capabilities resemble that of thalattosuchians. A suite of expanded sense organs (e.g., bony olfactory lamina; hypertrophied vestibule of the inner ear), and the clear expansion of the cerebrum to a more symmetrical and spherical shape suggest that dyrosaurids possess neuroanatomical modifications facilitating an agile predatory near-shore ecology.

Palaeobiology of the reclining rangeomorph Beothukis from the Ediacaran Mistaken Point Formation of southeastern Newfoundland

Beothukis mistakensis from the Ediacaran System of Newfoundland, Canada demonstrates complex fractal-like morphology through the development of primary-, secondary- and tertiary-order Rangea-like units. The primary-order rangeomorph units observed in B. mistakensis are tightly juxtaposed, show no evidence of being independent of one another and are made up of chamber-like secondary-order – probably mesoglea-filled – units. The growth of these rangeomorph units demonstrates that the frond developed from the tip towards the basal region through ontogeny. The tertiary-order units of Beothukis are considered to represent surface morphology on the secondary-order units. This is in contrast to palaeobiological reconstructions of Beothukis that invoke three-dimensional fractal-like branches with independent units, which has been used to infer an osmotrophic mode of life. It is considered here that the fractal-like morphology of the lower surface of B. mistakensis was an adaptation to increase surface area to volume ratio. The quilted morphology of Beothukis proposed here is consistent with a sessile, reclining, phagocytotic and/or chemosymbiotic mode of life similar to that invoked for the reclining rangeomorph Fractofusus.

Dorsiflexory Wedge First Metatarsal Osteotomy: Does an Oblique Cut Increase Surface Area?

Category: Ankle Introduction/Purpose: A plantarflexed first metatarsal can contribute to a forefoot driven cavus foot deformity or result in plantar ulcerations from forefoot pressure overload in a neuropathic patient. Often, this deformity is managed via a dorsiflexon first metatarsal base osteotomy. This osteotomy is often described as a vertical wedge, with a dorsal base, in the proximal metatarsal. Alternatively we propose an oblique wedge, which may also allow for increased surface area for osseous healing to occur, in addition to being more theoretically stable to weightbearing with greater fixation options. Methods: Ten cadaveric below-knee specimens were randomized into an oblique wedge (5 specimens) and vertical wedge (5 specimens) groups. The osteotomies were performed by a single surgeon on the same date. Digital calipers were utilized to obtain measurements to calculate surface area for each osteotomy. Demographic data including patient age at death, height, weight, BMI, sex, and laterality were obtained. Results: The mean surface area of the proximal metatarsal for the vertical group was 298.2±76.5 mm2, whereas the oblique group was significantly larger at 538.6 ± 200.4 mm2 (CI 95%, p=0.0255). Similarily, but not to significance the distal side of the osteotomy demonstrated increased surface area for the oblique group with 397.8±191.4 mm2 compared to the vertical group with 265.8±75.3 mm2 (CI 95%, p=0.13. The groups were demographically similar, including height (CI 95%, p=0.62) and BMI (CI 95%, p=0.19). Conclusion: Our results demonstrate significantly greater surface area for the oblique dorsiflexory wedge first metatarsal osteotomy, compared to the vertical dorsiflexory wedge first metatarsal osteotomy. Further analysis is recommended for large cohort head-to-head clinical comparison of these techniques with consideration for cost effectiveness of fixation constructs, procedural complications and patient reported clinical outcome measures.

Pemanfaatan Lumpur Primer Industri Kertas sebagai Absorben

The Utilization of Primary Sludge from Paper Mills as AbsorbentAbstractThe primary sludge from paper mill contains cellulose fiber that has high absorption capacity and potential to be used as an absorbent for hydrophobic compounds. The utilization of primary sludge from paper mill using raw material of waste paper and virgin pulp to be used as an absorbent has been conducted. The stages process of absorbent fabrication was consisted of three stages such as drying, mechanical and chemical processes. Mechanical process conducted were crushing and grinding methods to increase surface area and pore volume of sludge. Meanwhile silanization process as chemical treatment using solution of γ-metacryloxypropyl trimethoxysilane in ethanol to improve the hydrophobic properties of primary sludge was also done. Absorbent products were tested for the maximum sorbency, the sorbent performance, absorption of hydrophobic liquid, absorption of hydrophobic dust, and contact angle test to conduct their performance. The absorbency of absorbent product which is covered by cushion material was also tested. Result indicated that the absorption performance of some absorbent product is higher than commercial absorbent on hydrophobic liquid and hydrophobic dust absorption test. But it was lower than commercial absorbent on maximum sorbency and the sorbent performance test. The use of cushion material as a wrapper could make it easy in the collection and could increase the absorbency.Keywords: primary sludge; mechanical; silanization; absorbent; hydrophobic AbstrakLumpur primer dari industri kertas mengandung serat selulosa yang memiliki daya serap tinggi dan memiliki potensi dimanfaatkan sebagai absorben senyawa hidrofobik. Pemanfaatan lumpur primer industri kertas berbahan baku kertas bekas dan virgin pulp sebagai absorben telah dilakukan. Tahapan proses pembuatan absorben dari lumpur primer meliputi proses pengeringan, proses mekanis, dan proses kimia. Proses mekanis yang dilakukan adalah crushing dan grinding untuk meningkatkan luas permukaan dan volume pori-pori lumpur dilanjutkan dengan proses silanisasi (silanization) sebagai perlakuan kimia menggunakan larutan γ-metacryloxypropyl trimethoxysilane dalam etanol untuk meningkatkan sifat hidrofobik lumpur. Produk absorben diuji daya serap maksimum (maximum sorbency), kinerja absorben, penyerapan cairan hidrofobik, penyerapan debu hidrofobik, dan pengujian sudut kontak. Daya serap produk absorben yang ditutup bahan bahan cushion juga diuji. Hasil menunjukkan kemampuan absorbsi cairan hidrofobik dan debu hidrofobik dari beberapa perlakuan produk absorben lebih tinggi dari absorben komersial, sedangkan hasil maximum sorbency dan uji kinerja absorben menunjukkan hasil lebih rendah dari absorben komersial. Penggunaan bahan cushion sebagai pembungkus dapat memudahkan dalam pengumpulan dan dapat meningkatkan penyerapan.Kata kunci: lumpur primer; mekanis; silanisasi; absorben; hidrofobik

Food procurement and processing

Fish display a wide range of adaptations of the mouth and pharynx for specific feeding patterns including planktivory, fin-biting, picking and scraping. Appetite control is complex, involving stimulatory and inhibitory hormones. The gut has a linear plan similar to other vertebrates but with considerable variation between taxa, and a stomach may be absent. Many bony fish possess pyloric caeca, containing digestive enzymes, and may increase surface area for digestion. In chondrichthyes (sharks, etc.), a ‘spiral valve’ increases surface area of the intestine. Smooth muscle contractions in the gut wall pass food along the tract under control of food pressure, the autonomic nervous system and specific peptides. Digestion by hydrolytic enzymes, and absorption occur in the intestine, monomers produced being absorbed mainly through transcellular routes, involving enterocytes, into the blood of the hepatic portal vein to the liver. Dietary requirements and nutrition are discussed.