Search

Your search keyword '"Kotob S"' showing total 39 results
Start Over Author "Kotob S"
39 results on '"Kotob S"'

3. Hydrocracker advanced control improves profitability

Author

Maheshri, J. C., Kotob, S., and Yousuf, B. H.

Subjects
Kuwait National Petroleum Company, K.S.C. -- Production management, Cracking process -- Methods, Petroleum industry -- Production management -- Methods, Petroleum -- Production management -- Methods, Business, Petroleum, energy and mining industries, Production management, Methods
Abstract

This refinery maximized jet fuel yield, while minimizing hydrogen consumption Mina Al-Ahmadi refinery is the oldest and largest refinery in Kuwait with over 400,000 bpsd capacity. It is owned and [...]

Published
2000

5. Analysis and application of minimum variance discrete time system identification

Author

Kotob, S and Kaufman, H

Subjects
Computer Programming And Software
Abstract

An on-line minimum variance parameter identifier was developed which embodies both accuracy and computational efficiency. The new formulation resulted in a linear estimation problem with both additive and multiplicative noise. The resulting filter is shown to utilize both the covariance of the parameter vector itself and the covariance of the error in identification. It is proven that the identification filter is mean square covergent and mean square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm.

Published
1976

6. Minimum variance system identification with application to digital adaptive flight control

Author

Kotob, S and Kaufman, H

Subjects
Aircraft Stability And Control
Abstract

A new on-line minimum variance filter for the identification of systems with additive and multiplicative noise is described which embodies both accuracy and computational efficiency. The resulting filter is shown to use both the covariance of the parameter vector itself and the covariance of the error in identification. A bias reduction scheme can be used to yield asymptotically unbiased estimates. Experimental results for simulated linearized lateral aircraft motion in a digital closed loop mode are presented, showing the utility of the identification schemes.

Published
1975

7. Analysis and application of minimum variance discrete time system identification

Author

Kaufman, H and Kotob, S

Subjects
Cybernetics
Abstract

An on-line minimum variance parameter identifier is developed which embodies both accuracy and computational efficiency. The formulation results in a linear estimation problem with both additive and multiplicative noise. The resulting filter which utilizes both the covariance of the parameter vector itself and the covariance of the error in identification is proven to be mean square convergent and mean square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm.

Published
1975

8. Digital adaptive flight controller development

Author

Kaufman, H, Alag, G, Berry, P, and Kotob, S

Subjects
Aircraft Stability And Control
Abstract

A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Two designs are described for an example aircraft. Each of these designs uses a weighted least squares procedure to identify parameters defining the dynamics of the aircraft. The two designs differ in the way in which control law parameters are determined. One uses the solution of an optimal linear regulator problem to determine these parameters while the other uses a procedure called single stage optimization. Extensive simulation results and analysis leading to the designs are presented.

Published
1974

9. Digital system identification and its application to digital flight control

Author

Kotob, S and Kaufman, H

Subjects
Electronics
Abstract

On-line system identification of linear discrete systems for implementation in a digital adaptive flight controller is considered by the conventional extended Kalman filter and a decoupling process in which the linear state estimation problem and the linear parameter identification problem are each treated separately and alternately. Input requirements for parameter identifiability are established using the standard conditions of observability for a time variant system. Experimental results for simulated linearized lateral aircraft motion are included along with the effect of different initialization and updating procedures for the priming trajectory used by the filter.

Published
1974

10. Analysis and application of minimum variance discrete linear system identification

Author

Kotob, S and Kaufman, H

Subjects
Cybernetics
Abstract

An on-line minimum variance (MV) parameter identifier is developed which embodies both accuracy and computational efficiency. The formulation results in a linear estimation problem with both additive and multiplicative noise (AMN). The resulting filter which utilizes both the covariance of the parameter vector itself and the covariance of the error in identification is proven to be mean-square convergent and mean-square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm.

Published
1977

11. Effects of polymerization on the hypertensive action of diaspirin cross-linked hemoglobin in rats

Author

Abassi, Z, Kotob, S, Pieruzzi, F, Abouassali, M, Keiser, H, Fratantoni, J, Alayash, A, Alayash, A., PIERUZZI, FEDERICO UMBERTO EMILIO GUGLIE, Abassi, Z, Kotob, S, Pieruzzi, F, Abouassali, M, Keiser, H, Fratantoni, J, Alayash, A, Alayash, A., and PIERUZZI, FEDERICO UMBERTO EMILIO GUGLIE

Abstract

It is believed that the hypertensive effect of diaspirin crosslinked hemoglobin, a viable blood substitute, can be resolved by polymerization, which reduces the diffusion of this derivative into the interstitial space between nitric oxide-producing endothelium and the target vascular smooth muscle. We studied the systemic and renal responses to infusion of three cell-free human hemoglobins in anesthetized isovolemic rats: unmodified (HbA0), crosslinked (alpha-DBBF), and polymerized crosslinked (poly alpha-DBBF). HbA0 produced a significant increase in mean arterial blood pressure (MAP) throughout the 60-minute infusion. alpha-DBBF, on the other hand, produced a more marked and prolonged increase in MAP over 120 minutes. Only a moderate increase in MAP was observed in rats after a 30-minute infusion with poly alpha-DBBF. The extent of renal insufficiency produced by these proteins, as determined by the glomerular filtration rate, was in the following order: HbA0 > poly alpha-DBBF > alpha-DBBF. Infusion of poly alpha-DBBF, under hypovolemic but not isovolemic conditions in rats, produced an increase in heart rate, cardiac output, and stroke volume and a decrease in total peripheral resistance after 60 minutes. Chemical polymerization to increase the size of alpha-DBBF does not appear to improve its hemodynamic properties in rats, especially under partial exchange transfusion, a more clinically relevant indication for a hemoglobin-based blood substitute.

Published
1997

12. Pulmonary and renal neutral endopeptidase EC 3.4.24.11 in rats with experimental heart failure

Author

Abassi, Z, Kotob, S, Golomb, E, Pieruzzi, F, Keiser, H, Keiser, H., PIERUZZI, FEDERICO UMBERTO EMILIO GUGLIE, Abassi, Z, Kotob, S, Golomb, E, Pieruzzi, F, Keiser, H, Keiser, H., and PIERUZZI, FEDERICO UMBERTO EMILIO GUGLIE

Abstract

Congestive heart failure is characterized by avid sodium retention and a blunted renal response to exogenous and endogenous atrial natriuretic peptide. Inhibition of neutral endopeptidase EC 3.4.24.11, the main enzyme that degrades natriuretic peptides, produces a natriuretic response in different models of congestive heart failure. This raises the possibility that an increase in either the expression or activity of neutral endopeptidase is responsible for these phenomena. In the present study, we examined (1) the renal effects of SQ-28,603, a neutral endopeptidase inhibitor, in rats with moderate and severe congestive heart failure induced by an aortocaval fistula compared with sham controls, and (2) neutral endopeptidase expression and activity in the lungs and kidneys of these rats. Infusion of SQ-28,603 (40 mg/kg IV) induced a significant natriuretic response in normal rats and rats with moderate congestive heart failure. This response was blunted in rats with severe congestive heart failure. Surprisingly, renal neutral endopeptidase mRNA levels, assessed by quantitative reverse transcriptase-polymerase chain reaction; protein levels, assessed by Western blotting; and activity, assessed by gelatin gels, were comparable in all groups. Pulmonary neutral endopeptidase mRNA levels decreased by 45% in rats with severe congestive heart failure but not in rats with mild congestive heart failure. In addition, pulmonary neutral endopeptidase immunoreactivity levels and activity were significantly decreased in congestive heart failure in correlation with the severity of the disorder.(ABSTRACT TRUNCATED AT 250 WORDS)

Published
1995

26. Adaptive Bioreactor Identification Using Sensitivity of Process Stoichiometry

Author

Kotob, S., Albrecht, C., Juraidan, M., and Kafeety, H.

Abstract

A dynamic mathematical model of biotechnological process (single-cell protein process) was derived using process stoichiometry and material balancing. The accuracy of nonlinear (EKF) and linear estimators (least squares) in identifying culture parameters and state of the continuous SCP process was determined. A bias term was observed between experimental and estimation results. The sensitivity of the off-gas analysis measurement used to estimate yield coefficient and biomass concentration was determined with respect to biomass composition. An adaptive technique to select between two models representing with or without metabolic product formation was developed using an optimal Bayes decision. The application of the developed methodology to the SCP process gave reliable estimates of process state variables close to the off-line experimental results. The method can be used to implement adaptive controls on continuous fermentation processes.

Published
1987
Full Text
View/download PDF

32. Effects of polymerization on the hypertensive action of diaspirin cross-linked hemoglobin in rats

Author

Shaban Kotob, Zaid Abassi, Federico Pieruzzi, Majd Abouassali, Joseph C. Fratantoni, Harry R. Keiser, Abdu I. Alayash, Abassi, Z, Kotob, S, Pieruzzi, F, Abouassali, M, Keiser, H, Fratantoni, J, and Alayash, A

Subjects
Male, Cardiac output, Vascular smooth muscle, Hemodynamics, Blood Pressure, Polyethylene Glycol, Muscle, Smooth, Vascular, Blood substitute, Polyethylene Glycols, Rats, Sprague-Dawley, Hemoglobins, Heart Rate, Cardiac Output, Aorta, Chemistry, General Medicine, medicine.anatomical_structure, Cross-Linking Reagents, NG-Nitroarginine Methyl Ester, Enzyme Induction, Hypertension, Human, Glomerular Filtration Rate, medicine.medical_specialty, Endothelium, Cross-Linking Reagent, Pathology and Forensic Medicine, Blood Substitute, Blood Substitutes, Internal medicine, medicine, Animals, Humans, Hemodynamic, Hemoglobin, Analysis of Variance, Aspirin, Animal, Sodium, Stroke Volume, Surgery, Rats, Endocrinology, Blood pressure, Vascular resistance, Potassium, Rat, Vascular Resistance, Endothelium, Vascular, Nitric Oxide Synthase
Abstract

It is believed that the hypertensive effect of diaspirin crosslinked hemoglobin, a viable blood substitute, can be resolved by polymerization, which reduces the diffusion of this derivative into the interstitial space between nitric oxide-producing endothelium and the target vascular smooth muscle. We studied the systemic and renal responses to infusion of three cell-free human hemoglobins in anesthetized isovolemic rats: unmodified (HbA0), crosslinked (alpha-DBBF), and polymerized crosslinked (poly alpha-DBBF). HbA0 produced a significant increase in mean arterial blood pressure (MAP) throughout the 60-minute infusion. alpha-DBBF, on the other hand, produced a more marked and prolonged increase in MAP over 120 minutes. Only a moderate increase in MAP was observed in rats after a 30-minute infusion with poly alpha-DBBF. The extent of renal insufficiency produced by these proteins, as determined by the glomerular filtration rate, was in the following order: HbA0 > poly alpha-DBBF > alpha-DBBF. Infusion of poly alpha-DBBF, under hypovolemic but not isovolemic conditions in rats, produced an increase in heart rate, cardiac output, and stroke volume and a decrease in total peripheral resistance after 60 minutes. Chemical polymerization to increase the size of alpha-DBBF does not appear to improve its hemodynamic properties in rats, especially under partial exchange transfusion, a more clinically relevant indication for a hemoglobin-based blood substitute.

Published
1997

33. Pulmonary and renal neutral endopeptidase EC 3.4.24.11 in rats with experimental heart failure

Author

Shaban Kotob, Zaid Abassi, Harry R. Keiser, Federico Pieruzzi, Eliahu Golomb, Abassi, Z, Kotob, S, Golomb, E, Pieruzzi, F, and Keiser, H

Subjects
Male, medicine.medical_specialty, Molecular Sequence Data, Endogeny, Kidney, Polymerase Chain Reaction, Sodium balance, Rats, Sprague-Dawley, Downregulation and upregulation, Atrial natriuretic peptide, Internal medicine, Internal Medicine, medicine, Animals, RNA, Messenger, Neprilysin, Lung, chemistry.chemical_classification, Heart Failure, Alanine, Base Sequence, Animal, business.industry, medicine.disease, Rats, Blot, Endocrinology, Enzyme, chemistry, Heart failure, Rat, business
Abstract

Abstract Congestive heart failure is characterized by avid sodium retention and a blunted renal response to exogenous and endogenous atrial natriuretic peptide. Inhibition of neutral endopeptidase EC 3.4.24.11 , the main enzyme that degrades natriuretic peptides, produces a natriuretic response in different models of congestive heart failure. This raises the possibility that an increase in either the expression or activity of neutral endopeptidase is responsible for these phenomena. In the present study, we examined (1) the renal effects of SQ-28,603, a neutral endopeptidase inhibitor, in rats with moderate and severe congestive heart failure induced by an aortocaval fistula compared with sham controls, and (2) neutral endopeptidase expression and activity in the lungs and kidneys of these rats. Infusion of SQ-28,603 (40 mg/kg IV) induced a significant natriuretic response in normal rats and rats with moderate congestive heart failure. This response was blunted in rats with severe congestive heart failure. Surprisingly, renal neutral endopeptidase mRNA levels, assessed by quantitative reverse transcriptase–polymerase chain reaction; protein levels, assessed by Western blotting; and activity, assessed by gelatin gels, were comparable in all groups. Pulmonary neutral endopeptidase mRNA levels decreased by 45% in rats with severe congestive heart failure but not in rats with mild congestive heart failure. In addition, pulmonary neutral endopeptidase immunoreactivity levels and activity were significantly decreased in congestive heart failure in correlation with the severity of the disorder. We conclude that an increase in neutral endopeptidase expression or activity does not occur in rats with congestive heart failure, and therefore, an upregulation of neutral endopeptidase is unlikely to account for the blunted natriuretic response to the atrial natriuretic peptide and the positive sodium balance in congestive heart failure.

Published
1995

34. Mycobacterium shottsii sp. nov., a slowly growing species isolated from Chesapeake Bay striped bass (Morone saxatilis).

Author

Rhodes MW, Kator H, Kotob S, van Berkum P, Kaattari I, Vogelbein W, Quinn F, Floyd MM, Butler WR, and Ottinger CA

Subjects
Animals, Fish Diseases epidemiology, Molecular Sequence Data, Mycobacterium genetics, Mycobacterium growth & development, Mycobacterium isolation & purification, Mycobacterium Infections epidemiology, Mycobacterium Infections microbiology, Phenotype, Phylogeny, RNA, Bacterial genetics, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Bass microbiology, Fish Diseases microbiology, Mycobacterium classification, Mycobacterium Infections veterinary, RNA, Ribosomal, 16S analysis
Abstract

Slowly growing, non-pigmented mycobacteria were isolated from striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. Growth characteristics, acid-fastness and results of 16S rRNA gene sequencing were consistent with those of the genus Mycobacterium. A unique profile of biochemical reactions was observed among the 21 isolates. A single cluster of eight peaks identified by analysis of mycolic acids (HPLC) resembled those of reference patterns but differed in peak elution times from profiles of reference species of the Mycobacterium tuberculosis complex. One isolate (M1 75T) was placed within the slowly growing mycobacteria by analysis of aligned 168S rRNA gene sequences and was proximate in phylogeny to Mycobacterium ulcerans and Mycobacterium marinum. However, distinct nucleotide differences were detected in the 16S rRNA gene sequence among M175T, M. ulcerans and M. marinum (99.2% similarity). Isolate M175T could be differentiated from other slowly growing, non-pigmented mycobacteria by its inability to grow at 37 degrees C, production of niacin and urease, absence of nitrate reductase and resistance to isoniazid (1 microg ml(-1)), thiacetazone and thiophene-2-carboxylic hydrazide. Based upon these genetic and phenotypic differences, isolate M175T (=ATCC 700981T =NCTC 13215T) is proposed as the type strain of a novel species, Mycobacterium shottsii sp. nov.

Published
2003
Full Text
View/download PDF

35. A unique Mycobacterium species isolated from an epizootic of striped bass (Morone saxatilis).

Author

Rhodes MW, Kator H, Kotob S, van Berkum P, Kaattari I, Vogelbein W, Floyd MM, Butler WR, Quinn FD, Ottinger C, and Shotts E

Subjects
Animals, Fish Diseases epidemiology, Genes, rRNA, Molecular Sequence Data, Mycobacterium genetics, Mycobacterium Infections epidemiology, Mycobacterium Infections microbiology, Phenotype, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Skin Ulcer microbiology, Skin Ulcer veterinary, Bass microbiology, Fish Diseases microbiology, Mycobacterium classification, Mycobacterium isolation & purification, Mycobacterium Infections veterinary
Abstract

We isolated a Mycobacterium sp. resembling Mycobacterium marinum and M. ulcerans from diseased striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. This isolate may represent an undescribed Mycobacterium species, based on phenotypic characteristics and comparative 16S rRNA gene sequence.

Published
2001
Full Text
View/download PDF

36. Characterization of two Perkinsus spp. from the softshell clam, Mya arenaria using the small subunit ribosomal RNA gene.

Author

Kotob SI, McLaughlin SM, van Berkum P, and Faisal M

Subjects
Animals, Apicomplexa isolation & purification, Cloning, Molecular, Gills parasitology, Hemolymph parasitology, Molecular Sequence Data, Polymerase Chain Reaction, Polymorphism, Restriction Fragment Length, Restriction Mapping, Sequence Analysis, DNA, Apicomplexa classification, Apicomplexa genetics, Bivalvia parasitology, Genes, Protozoan, Genes, rRNA
Abstract

Sequence analysis and riboprinting of the small subunit ribosomal RNA genes were used to characterize two morphologically different Perkinsus species isolates from the gill (G117) and the hemolymph (H49) of the softshell clam, Mya arenaria. Sequence data of the polymerase chain reaction amplified ribosomal RNA loci of G117 and H49 indicated that these genes are 1803 and 1806 base-pair long, respectively. A sequence similarity of > 98.9% was calculated among ribosomal RNA sequences of the two isolates of this study and the published sequences of Perkinsus marinus from the American eastern oyster, Crassostrea virginica, and Perkinsus sp. from the blood cockle of the Australian mollusc, Anadara trapezia. From a phylogenetic tree obtained from Jukes-Cantor distances of the aligned ribosomal RNA gene sequences of 13 eukaryotic taxa using the Neighbor-Joining method, we showed that G117 and H49 clustered within the genus Perkinsus. Guided by the sequence data of Perkinsus marinus (accession # X75762) and Perkinsus sp. (accession # L07375), restriction endonucleases were selected for restriction fragment analysis of polymerase chain reaction products of the small subunit ribosomal RNA genes (riboprinting). Riboprinting was used to distinguish the four members of the genus Perkinsus from each other.

Published
1999
Full Text
View/download PDF

37. Effects of polymerization on the hypertensive action of diaspirin cross-linked hemoglobin in rats.

Author

Abassi Z, Kotob S, Pieruzzi F, Abouassali M, Keiser HR, Fratantoni JC, and Alayash AI

Subjects
Analysis of Variance, Animals, Aorta drug effects, Aorta physiology, Aorta physiopathology, Cardiac Output drug effects, Endothelium, Vascular drug effects, Endothelium, Vascular enzymology, Endothelium, Vascular physiology, Enzyme Induction, Glomerular Filtration Rate drug effects, Heart Rate drug effects, Hemoglobins isolation & purification, Humans, Hypertension physiopathology, Male, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular physiology, Muscle, Smooth, Vascular physiopathology, NG-Nitroarginine Methyl Ester pharmacology, Nitric Oxide Synthase biosynthesis, Polyethylene Glycols, Potassium urine, Rats, Rats, Sprague-Dawley, Sodium urine, Stroke Volume drug effects, Vascular Resistance drug effects, Aspirin analogs & derivatives, Blood Pressure drug effects, Blood Substitutes toxicity, Cross-Linking Reagents, Hemodynamics drug effects, Hemoglobins toxicity, Hypertension chemically induced
Abstract

It is believed that the hypertensive effect of diaspirin crosslinked hemoglobin, a viable blood substitute, can be resolved by polymerization, which reduces the diffusion of this derivative into the interstitial space between nitric oxide-producing endothelium and the target vascular smooth muscle. We studied the systemic and renal responses to infusion of three cell-free human hemoglobins in anesthetized isovolemic rats: unmodified (HbA0), crosslinked (alpha-DBBF), and polymerized crosslinked (poly alpha-DBBF). HbA0 produced a significant increase in mean arterial blood pressure (MAP) throughout the 60-minute infusion. alpha-DBBF, on the other hand, produced a more marked and prolonged increase in MAP over 120 minutes. Only a moderate increase in MAP was observed in rats after a 30-minute infusion with poly alpha-DBBF. The extent of renal insufficiency produced by these proteins, as determined by the glomerular filtration rate, was in the following order: HbA0 > poly alpha-DBBF > alpha-DBBF. Infusion of poly alpha-DBBF, under hypovolemic but not isovolemic conditions in rats, produced an increase in heart rate, cardiac output, and stroke volume and a decrease in total peripheral resistance after 60 minutes. Chemical polymerization to increase the size of alpha-DBBF does not appear to improve its hemodynamic properties in rats, especially under partial exchange transfusion, a more clinically relevant indication for a hemoglobin-based blood substitute.

Published
1997
Full Text
View/download PDF

38. Pulmonary and renal neutral endopeptidase EC 3.4.24.11 in rats with experimental heart failure.

Author

Abassi ZA, Kotob S, Golomb E, Pieruzzi F, and Keiser HR

Subjects
Alanine analogs & derivatives, Alanine pharmacology, Animals, Base Sequence, Kidney drug effects, Male, Molecular Sequence Data, Neprilysin antagonists & inhibitors, Neprilysin genetics, Polymerase Chain Reaction, RNA, Messenger analysis, Rats, Rats, Sprague-Dawley, Heart Failure enzymology, Kidney enzymology, Lung enzymology, Neprilysin physiology
Abstract

Congestive heart failure is characterized by avid sodium retention and a blunted renal response to exogenous and endogenous atrial natriuretic peptide. Inhibition of neutral endopeptidase EC 3.4.24.11, the main enzyme that degrades natriuretic peptides, produces a natriuretic response in different models of congestive heart failure. This raises the possibility that an increase in either the expression or activity of neutral endopeptidase is responsible for these phenomena. In the present study, we examined (1) the renal effects of SQ-28,603, a neutral endopeptidase inhibitor, in rats with moderate and severe congestive heart failure induced by an aortocaval fistula compared with sham controls, and (2) neutral endopeptidase expression and activity in the lungs and kidneys of these rats. Infusion of SQ-28,603 (40 mg/kg IV) induced a significant natriuretic response in normal rats and rats with moderate congestive heart failure. This response was blunted in rats with severe congestive heart failure. Surprisingly, renal neutral endopeptidase mRNA levels, assessed by quantitative reverse transcriptase-polymerase chain reaction; protein levels, assessed by Western blotting; and activity, assessed by gelatin gels, were comparable in all groups. Pulmonary neutral endopeptidase mRNA levels decreased by 45% in rats with severe congestive heart failure but not in rats with mild congestive heart failure. In addition, pulmonary neutral endopeptidase immunoreactivity levels and activity were significantly decreased in congestive heart failure in correlation with the severity of the disorder.(ABSTRACT TRUNCATED AT 250 WORDS)

Published
1995
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results