1,721,091 research outputs found
Phytofiltration of arsenic and cadmium by using an aquatic plant, Micranthemum umbrosum: Phytotoxicity, uptake kinetics, and mechanism
Full text linkArsenic (As) and cadmium (Cd) are noxious and carcinogenic pollutants that can be removed from water by using emerging, ecofriendly, phytofiltration technology that employs Micranthemum umbrosum. After culturing M. umbrosum for 7 days in a hydroponic experiment, accumulation of 1219±44.11 µg As g−1 and 799.40±30.95 µg Cd g−1 were observed in the leaves, from 1000 µg As L−1 and 1000 µg Cd L−1 of water, respectively. Plant and water samples were analyzed for assessing the As and Cd accumulations, translocations, phytotoxic effects, uptake mechanisms and kinetics, and for evaluating the potential of M. umbrosum in As and Cd phytofiltration. The uptake pattern was leaf>stem>root for both pollutants. The plant showed higher resistance to As than to that to Cd. Uptake of inorganic As species was much greater than that of organic As and was found at above the substrate concentration. However, Cd showed similar uptake pattern to that of inorganic As species, and the data was better fit to a non-linear than a linear model. Low molecular weight substances that have thiol group(s) may be responsible for the binding of As in plants whereas Cd showed a different mechanism to that of As. M. umbrosum showed good As phytofiltration capabilities without any phytotoxic effects, but it was found to be a moderate accumulator of Cd with some phytotoxic effect compare to some other previously studied plant
Indoor positioning through integration of optical angles of arrival with an inertial measurement unit
No full textA novel indoor positioning solution is proposed in this work. An inertial navigation system (INS) is integrated with optical angle of arrival (OAOA) measurements to yield a smoother, more accurate, and robust positioning solution for indoor environments. An extended Kalman filter (EKF) is used to integrate the INS and OAOA measurements.
Four different algorithms are proposed for the novel indoor positioning solution by INS/OAOA integration. An error state Kalman filter is used for implementing all four algorithms. In previous work, magnetometer error estimation was not included in the EKF state vector. In this work, magnetometer error estimation is added to the EKF state vector, and this reduced the average position error by 3.7% to 7%. Quaternion algebra is used instead of Euler angles due to the possibility of mathematical singularities for certain Euler angles. Quaternion vector estimation is performed by adding the quaternion vector to the state vector of the EKF.
Both loosely coupled and tightly coupled integration strategies are explored for INS/OAOA integration. The tightly coupled strategy reduces the average positioning error by 60% compared to an OAOA-only system while the loosely coupled strategy reduces the average error by 44%. However, the performance improvement of the tightly coupled system comes with an increased computational cost due to nonlinearities in the measurement model.
The loosely and tightly coupled algorithms are modified by augmenting the observation vector with a prior accelerometer bias estimate and a quaternion vector estimate. This results in loosely and tightly coupled algorithms with augmented observations. The algorithms with augmented observations perform significantly better, especially in a case of the low update rate for the OAOA sensor. An average position error of 4.89 cm is reduced to 3.11 cm by using the loosely coupled algorithm with augmented observations instead of the loosely coupled algorithm without observation augmentation. This is an improvement of approximately 36%. For the tightly coupled system, this improvement is approximately 32%. However, where the update rate from the OAOA sensor is fast enough, no significant performance improvement is observed by using algorithms with augmented observations.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat
Phytofiltration of arsenic and cadmium from the water environment using Micranthemum umbrosum [an abstract of dissertation and a summary of dissertation review]
No full textINFLUENCE OF PLANT SPACING AND WEED MANAGEMENT METHODS ON THE YIELD OF WHITE JUTE (Corchorus capsularis)
Full text linkA Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
in Partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE (MS)
IN
AGRONOMYA field experiment was conducted at Sher-e-Bangla Agricultural University.
Dhaka during April to August, 2009 with a view to find out the influence of
plant spacing and weed management methods on the yield of white jute
(var.CVL- 1). The experiment consisted of four weed control methods
viz,
two
times hand weeding with one raking, herbicide Whip Super 9 EC (FenoxapropP-ethyl:
C
13H16C1N05
)
application at 15 DAS, two times hand weeding at 20+40
DAS and three times hand weeding at 15+30+45 DAS and Ibur plant spacing
viz.,
20 cm x 10 cm, 25 cm x 10 cm. 30 cm x 10 cm (20, 25 and 30 cm row to
row with plants spaced at 10 cm intervals in the row) and broadcasting. The
dominant grass weeds were Cynodon dactylon
(43%), Echinochloa colonam
(29%) and
Eleusine india
(22%). Results showed that plant spacing differed
significantly and 25 cm x 10 cm spacing gave the highest (3.12 t ha") fibre yield
which was statistically similar with 20 cm x 10 cm. Two times weeding and one
raking gave the highest (3.12 t
hi')
fibre yield which was statistically similar
with herbicide application (2.97 t ha"). Interaction effect showed highest fiber
yield (4.02 t ha") was obtained from 20 cm x 10 cm spacing with herbicide
application. Whip Super 9 EC @ 615 ml ha" effectively controlled the grass
weeds providing higher fibre yield and net 7.13 taka return per taka invested
whereas 6.51, 5.18 and 5.34 taka from two times hand weeding with one raking,
two times hand weeding and three times hand weeding, respectively
Manufacturing and mechanics of polymer matrix composites
Full text linkFiber-reinforced composite materials are widely used in the aerospace and automobile industries. Their strength-to-weight and stiffness-to-weight ratios make them suitable to be used in spacecraft, especially as cryogenic tank materials. One of the focus of this dissertation is to investigate the application of woven carbon and Kevlar® fiber composites as cryogenic tank materials. Tensile, bending and short beam shear tests are performed on rectangular specimens at room temperature and after cryogenic exposure (-196°C). It is found that the mechanical properties of these composite materials do not degrade significantly due to cryogenic exposure. It is observed that the failure mode took place before and after the cryogenic exposure is identical, which implies that the carbon and Kevlar® fiber composite can be used as a cryogenic tank materials. Hybridization of this two types of composites (carbon and Kevlar® fiber) is also studied. A computational study is conducted to reduce the number of experiments, and to find the optimum combination of carbon and Kevlar ® fiber reinforcements. Thirty different combinations of hybrid composites are studied computationally and six of these combinations are found suitable based on minimum number of peak stress and minimum peak stress value. This six optimum combinations along with some other combinations are manufactured by using the Vacuum Assisted Resin Transfer Molding (VARTM) process to facilitate comparative study. Comparison of mechanical test results performed on full cryogenic exposure, gradient exposure and pristine materials shows that the hybrid composites can be used as cryogenic tank materials. Another important aspect of this dissertation is to study the inter-laminar reinforcement of multi-directional laminates by using additive manufacturing technology. Under thermos-mechanical loading, very high stress can be developed at the interfaces due to property mismatch between different plies leading to premature failure. In order to reinforce those interfaces, it is very important to identify these delamination prone interfaces. A novel semi-analytical model is developed to find the delamination prone interfaces in a multidirectional laminates under thermo-mechanical loading and the results of this model is compared with previously published results. Very thin lines of polylactic acid (PLA) are printed on the critical interfaces in multi-directional laminate by using MakerBot Replicator Desktop 3D printer and it is found that, inter-laminar shear strength (ILSS) is increased by approximately 28%. So, the additive manufacturing technology can be used to increase inter-laminar strength of multi-directional laminate
Julia Set as a Martin Boundary
Full text linkDie Julia-Menge der Klasse hyperbolischer rationaler Abbildungen, deren Julia-Menge vollständig unzusammenhängend ist, wird hier identifiziert als die Martin-Grenze (Martin boundary) einer Markovkette durch die Anwendung der Theorie symbolischer Dynamik. Diese Beziehung ermöglicht es, einige thermodynamische Konzepte, wie Entropie, Maß der maximalen Entropie, des Gibbs-Maßes und des Gleichgewichtmaßes, auf potenzialtheoretische Konzepte wie Kapazität und harmonische Maße auf der Julia Menge, auf der eine geeignete Potenzialfunktion definiert ist, zu beziehen. Wir haben hier z.B. das Maß der maximalen Entropie für eine rationale Abbildung auf der Julia Menge identifiziert; es ist einfach das Bildmaß eines bestimmten Bernoulli-Maßes auf dem Schiebungsraum (shift space). Wir haben weiter bewiesen, dass das harmonische Maß auf der Julia-Menge das Bildmaß eines nicht-atomaren, quasi-invarianten, konservativen Maßes auf dem einseitigen Schiebungsraum ist. Wir haben gezeigt, dass dieses quasi-invariante Maß ein Gibbs-Maß darstellt und es mit einem Bernoulli-Maß äquivalent ist. Durch Anwendung des Ruelle-Perron-Frobenius Satzes haben wir abgeleitet, dass das Gibbs-Maß zur Definition eines eindeutigen, gegenüber Verschiebung invarianten, Gleichgewichtsmaßes herangezogen werden kann. Wir haben weiter bewiesen, dass das Gleichgewichtmaß für das logarithmische Potenzial und das klassische harmonische Maß in unserem Fall übereinstimmen. Schließlich haben wir gezeigt, dass ein bestimmtes Dirichlet-Problem für das Fatou-Menge in unserem Fall eine eindeutige Lösung besitzt.The Julia set of the class of hyperbolic rational maps having a totally disconnected Julia set is here identified as the Martin boundary of a Markov chain by using symbolic dynamics. When the Julia set is also bounded, this connection allows one to relate various thermodynamic concepts, such as entropy, measure of maximal entropy, Gibbs measure, and measure of equilibrium, to potential theoretic concepts such as capacity and harmonic measures on the Julia set on which a suitable potential function is defined. We have identified the measure of maximal entropy for that class of rational maps on the Julia set; it is simply the image measure of a certain Bernoulli measure on the shift space. We have also proven that the harmonic measure on the Julia set is the image measure of a non-atomic, quasi-invariant, conservative measure on the one-sided shift space.We have further shown that this quasi-invariant measure is a Gibbs measure and is equivalent to a Bernoulli measure. By using the Ruelle-Perron-Frobenius theorem we have deduced that the Gibbs measure gives rise to a unique, shift-invariant equilibrium measure. We have further established that the measure of equilibrium for the logarithmic potential and the classical harmonic measure coincide in our case (with the Julia set being bounded and totally disconnected). Finally, we have proven that a certain Dirichlet problem for the Fatou domain in our case has a unique solution
Micranthemum umbrosumを用いた水圏環境よりのヒ素及びカドミウムの浄化
Full text linkHeavy metal pollution in aquatic environment due to natural sources and anthropogenicactivities, is posing a dreadful threat to the human health. Among different heavy metals,arsenic (As) and cadmium (Cd) are the two most toxic and carcinogenic agent that extensivelycontaminates the water bodies. There are some physical and chemical remediation methodsthat have some limitations like high production technology, costly, destruction of native microflora and fauna, and creation of secondary pollutions. In contrast, phytofiltration is a novel,cost effective, environmental friendly, aesthetic and solar-driven technology, using aquaticplants to remove As and Cd from contaminated water without causing any or little secondarypollution. A small number of aquatic plants were identified to uptake contaminants fromaquatic environment. Among them very few could accumulate more than one pollutant intheir bodies. Micranthemum umbrosum (J.F. Gmel) S.F. Blake, commonly known as Waterfern, Baby’s tears, or Pearl grass, belongs to the family Linderniaceae, is one of them, thatsignificantly absorbs both As and Cd from contaminated water.After culturing M. umbrosum for 7 days in a hydroponic experiment, the accumulation ofabout 1220 μg As g-1 and 800 μg Cd g-1 were observed in the leaves, from 1000 μg As L-1 and1000 μg Cd L-1 of water, respectively and it can removed 79.3–89.5% As and 60–73.1% Cdfrom 200 to 1000 μg As L-1 and 300 to 3000 μg Cd L-1 solutions, respectively. Plant andwater samples were analyzed for assessing the As and Cd accumulations, translocations,phytotoxic effects, uptake mechanisms and kinetics, and for evaluating the potential of M.umbrosum as As and Cd phytofiltrator.For As treatment, root to stem and stem to leaf translocation factors greater than 1.0 indicatedthat accumulation of As in leaves was large compared to that in stem and roots but there arelittle differences in accumulation of Cd in roots, leaves and stem. It is easy to clean up aquaticenvironment rather than soil due to most of the soil phytoremediators accumulatedcontaminants in their root parts which is sometimes very difficult to harvest and removal fromthe contaminated soil environment. However, the absorption pattern of As and Cd within M.umbrosum was leaf > stem > root. Bio-concentration factors (2350 for As and 3027 for Cd)for M. umbrosum were higher than for other As and Cd phytoremediators, indicates itshyperaccumulation of As and Cd from contaminated water environment. The analysis of different photosynthetic pigments and macro micro-nutrient concentration within plant bodyindicated that the plant showed more resistance to internal and external As concentrationsthan to that of Cd.Absorption uptake kinetics within M. umbrosum was studied by using Michaelis Mentenequation from different As species like arsenite, monomethylarsinic acid (MMAA),dimethylarsinic acid (DMAA) and Cd. The uptake of inorganic As species was much greaterthan that of organic As and was found at above the substrate concentration. Concentrationdependent arsenite and Cd uptake influx were linear up to 500 μg L-1 and after that decreased,probably due to the toxicological inhibition. However, Cd showed similar uptake pattern tothat of inorganic As species, and the data was better fitted to a non-linear than a linear model.Higher Vmax and lower Km value indicated that this plant has high affinity to uptake inorganicarsenite than Cd, organic MMAA and DMAA; and the uptake order was inorganic arsenite >Cd > MMAA > DMAA.As and Cd uptake mechanism within M. umbrosum was investigated by using Gelchromatography column made from Sephadex G-50 (fractionation range is about 1500-30000MW) and Sephadex G-15 (fractionation range is about 700-1500 MW) beads. After analysisof As, Cd, protein and thiol contents in each 2 mL fractionation collected from gel filtrationcolumn, we concluded that As within plants appeared to involve an induction of thiolsynthesis or binding with low molecular weight substances that have thiol group(s) whereasCd showed a different mechanism to that of As. Amino acid profile studied also showed thatCd uptaking mechanism and binding substances in M. umbrosum is different from algae andother plants which is not phytochelatin or thiol complex formation.M. umbrosum showed good As phytofiltration capabilities without any phytotoxic effects, butit was found to be a moderate accumulator of Cd with some phytotoxic effect and it can lowerthe As toxicity to a level (about 25 μg As L-1) close to the limit recommended by the WorldHealth Organization (10 μg As L-1) but below the limit recommended by Bangladesh andChina Government (50 μg As L-1). So M. umbrosum has the high As and Cd phytofiltrationpotency at low level (500 μg L-1) As and Cd contaminated water and it can be used asornamentation for room in addition to As and Cd accumulation from water, as it is popular as a green aquarium plant, from the aesthetic point of view of phytoremediation
EFFECT OF SALT INDUSTRIES BYPRODUCT AS A LIQUID FERTILIZER ON GROWTH AND YIELD OF LETTUCE IN SOILLESS CULTURE
Full text linkDEPARTMENT OF HORTICULTURE
SHER-E-BANGLA AGRICULTURAL UNIVERSITY
DHAKA-1207An experiment was conducted at the Central Laboratory in Sher-e-Bangla Agricultural
University, Dhaka; during September 2014 to March 2015 to identify the effect of salt industries
byproduct on growth and yield of lettuce in soilless culture. Three nutrient solutions were
considered as treatments, viz. T
– ½ Rahman and Inden (2012) + 0 ml of salt industries
byproduct (SIB), T
2
1
– ½ Rahman and Inden (2012) + 0.5 ml of SIB, T
– ½ Rahman and Inden
(2012) + 0.75 ml of SIB. The experiment was conducted in a completely randomized design
(CRD). Salt industries byproduct showed significant variation in most of the parameters. The
highest plant height (19.53 cm) was recorded from T
1
3
while the lowest plant height (15.61 cm)
was found in T
3
. Number of leaves per plant was maximum (10.61) from T
whereas minimum
(8.80) was recorded T
3
. Higher leaf breadth (11.36 cm) was recorded from T
1
which was
statistically similar to T
2
and lower (9.56 cm) was from T
, higher leaf length (17.61 cm) was
found in T
1
and lower (13.90 cm) was in T
3.
3
Maximum fresh weight of lettuce (48.81g/plant)
was recorded from T
1
which was statistically similar to T
and minimum (27.94 g/plant) was in
T
1
2
. In case of ascorbic acid content, the maximum amount of ascorbic acid content (157.61
mg/100g fresh weight) was recorded from T
and the minimum (127.41 mg/100g fresh weight of
lettuce) was in T
1
3
. In case of β-carotene content, the maximum amount of β-carotene content
(3207 µg/100g fresh weight of lettuce) was recorded from T
and the minimum (3100 µg/100g
fresh weight) was in T
1.
3
Similar trend was also found in other growth analytical parameters (viz.
leaf area, leaf area ratio, leaf mass ratio, root weight ratio, net assimilation ratio and relative
growth rate), which was the best from T
but LA, RGR and NAR were statistically similar to
that of T
2
1
. Meanwhile all the physiological parameters were lowest in T
(½
Rahman and Inden (2012) + 0.5 ml of SIB) can be used to get higher amount of ascorbic acid
and β-carotene content with moderate yieldA thesis
submitted to the Faculty of Agriculture
Sher-e-Bangla Agricultural University, Dhaka-1207
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
HORTICULTUR
ORDER-PROMISING AND PRODUCTION-PLANNING METHODS FOR SAWMILLS
No full textThis thesis focuses on the development of order-promising and production-planning methodologies for sawmills. Two types of demands are considered: contract and spot demands. Contract demands are those known commitments to be filled over a period of time, whereas spot demands are collected from the market for the current week, two, and three weeks prior to the delivery date. Campaigns are developed that describe how the various classes of logs will be processed under a given price list. The campaign produces lumber outputs that represent the proportions the sawmill optimizers would produce given this price list. An MIP model, which includes order promising and campaign production planning, is formulated to maximize revenue over a planning horizon. A new solution technique is introduced to simulate the effectiveness of the rolling planning horizon over the full year. The effectiveness of the solution techniques is studied using different scenarios
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Characterizing Therapy Induced Polyploidy (TIP) Populations as a Resistance Mechanism in DH/DE-DLBCL and Identifying Synthetic Lethal Targeted Therapies
No full textLymphoma is a blood cancer that involves the lymphatic system and is the 7th most common cancer in USA. Diffuse large B-cell lymphoma (DLBCL) and Peripheral T-cell lymphoma (PTCL) are the most common types of aggressive B-cell and T-cell non-Hodgkin lymphomas (NHL) respectively. Double-Hit or Double-Expresser DH/DE-DLBCL are high grade B-cell lymphomas characterized by translocation or over expression of MYC and BCL-2 which are mostly incurable with standard chemo-immunotherapy. Therefore, there is an unmet need for novel targeted therapy. Aurora kinase inhibition (alisertib) induces ~30% cell death (in vitro), while a portion of the remaining ~70% cells at day-4 escape apoptosis through polyploid populations which we called therapy induced polyploid cells (TIP). These TIP cells exhibited a high metabolic rate by increased AKT/mTOR and ERK/MAPK activity via BTK signaling through the chronic active B-cell receptor (BCR) pathway. TIP also showed increased levels of phospho-Hck and phospho-Akt indicating increased BCR signaling which is a rationale for combining ibrutinib (BTK inhibitor). Combined inhibition of AK + BTK reduced phosphorylation of AKT/mTOR and ERK-1/2, up-regulated phospho-H2A-X and Chk-2 (DNA damage), reduced Bcl-6 and decreased Bcl-2 and Bcl-xL results in induced apoptosis evident by PARP cleavage. In a DE-DLBCL SCID mouse xenograft model, ibrutinib alone was inactive, while alisertib + ibrutinib was additive with a tumor growth inhibition (TGI) rate of ~25%. However, TGI for ibrutinib + rituximab was ~50-60%. In contrast, triple therapy showed a TGI rate of >90%. Kaplan-Meier survival analysis showed 67% of mice were alive at day-89 with triple therapy versus only 20% with ibrutinib + rituximab. All treatments were well tolerated with no significant changes in body weights. Anti-DLBCL chemotherapy dosing schedules are intermittent, designed to avoid damage to normal tissue such as the mucous membranes, gut and the bone marrow. TIP are common in standard anti-DLBCL therapies (e.g. vincristine, doxorubicin) and thought to be responsible for disease relapse. Some of these TIP cells die but remaining of those are capable of re-entering the cell cycle during off-therapy periods. We discovered how these TIP cells can re-enter cell cycle and molecular mechanism underlying this resistance. We have purified AK inhibitor induced polyploid DH/DE-DLBCL cells by FACS. Time-lapse microscopy of single cells revealed that following drug removal, a subset of TIP cells divide and proliferate by reductive cell division(s). This includes multipolar mitosis, meiosis like nuclear fission or budding off daughter cells. RNA-Seq, Proteomics and Kinomics proling of TIP cells demonstrated that alisertib induced polyploid cells have up-regulated DNA damage response, replication and immune evasion; amplify receptor tyrosine kinase and T-cell receptor signaling; hijacks the spindle assembly checkpoint point control via MYC dysregulation of RanGAP1, TPX2 and KPNA2. We believe these up-regulated proteins are responsible for induction of aneuploid daughter cells and disease resistance and also provide potential opportunities for novel therapy combination that warrant further exploration. Lymphomas are systemic diseases that require a comprehensive knowledge of immune mechanism in cancer as well as targeted therapeutic approach for designing an optimal therapeutic strategy and desired synergy can be achieved by rational combination of small molecule inhibitors with immune modulatory agents that could enhance host immune response. In PTCL we have shown that expression of PD-L1 relative to PD-1 is high in PTCL biopsies ( 9-fold higher) and cell lines. Combination of alisertib with pan-PI3K inhibition or VCR significantly reduced PD-L1, NF-kB expression and inhibited phosphorylation of AKT, ERK1/2 and AK with enhanced apoptosis. In a syngeneic PTCL mouse xenograft model, alisertib demonstrated tumor growth inhibition (TGI) ~30%, whilst anti-PD-L1 therapy alone was ineffective. Alisertib + anti-PD-L1 resulted in TGI >90% indicative of a synthetic lethal interaction. PF-04691502 + alisertib + anti-PD-L1 + VCR resulted in TGI 100%. Overall, mice tolerated the treatments well. Co-targeting AK, PI3K and PD-L1 is a rational and novel therapeutic strategy for PTCL. In conclusion, we have identified therapeutic targets in aggressive B- and T-cell lymphoma which can be combined with immunotherapy that warrant investigation to disrupt rapid tumor evolution of TIP cells to mitigate disease relapse
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