Zvi Katz
University of Johannesburg, South Africa, Mechanical Engineering, Faculty Member
- Emeritus Professor of Mechanical Engineering, professional engineer , researcher and academic educator striving to a... moreEmeritus Professor of Mechanical Engineering, professional engineer , researcher and academic educator striving to advance knowledge and develop novel aspects of systems design and Manufacturing processes and systems through concepts based on nature , biological inspiration and emerging behavior.edit
Abstract The accuracy of an autonomous AGV in following a predetermined path is highly dependent on its navigational capability. Position recognition requires integrating communication, mapping, guidance, and navigation. The hardware and... more
Abstract The accuracy of an autonomous AGV in following a predetermined path is highly dependent on its navigational capability. Position recognition requires integrating communication, mapping, guidance, and navigation. The hardware and software development for such a system is presented. Aspects of the system's interaction are discussed and specific design attributes are evaluated and highlighted.
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The paper presents the main characteristics of search strategies used for automated pre-assembly engagement. The handling of such operations is described through an experimental set-up. Finally, experimental results are used to facilitate... more
The paper presents the main characteristics of search strategies used for automated pre-assembly engagement. The handling of such operations is described through an experimental set-up. Finally, experimental results are used to facilitate the decision-making process for correct automated engagement prior to the assembly insertion stage. The multi peg-hole system for preassembly engagement as a more complex system is discussed.
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... Maxim Integrated Products, Integrated Circuits Data Book, MIP, Inc, Sunnyvale CA (1989). FE Moslier and DI Schneider, Using Turbobasic, Osborne McGraw Hill, Berkeley (1988). ... Stephenson, JG, Cahill B., Microcomputer Troubleshooting... more
... Maxim Integrated Products, Integrated Circuits Data Book, MIP, Inc, Sunnyvale CA (1989). FE Moslier and DI Schneider, Using Turbobasic, Osborne McGraw Hill, Berkeley (1988). ... Stephenson, JG, Cahill B., Microcomputer Troubleshooting and Repair, Howard W. Sam & Co. ...
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using an acoustic emission (AE) based technique is proposed and tested. The model development is based on drilling with and without buns using standard twist drills. The objective of the work is to enable on-line prediction of burr... more
using an acoustic emission (AE) based technique is proposed and tested. The model development is based on drilling with and without buns using standard twist drills. The objective of the work is to enable on-line prediction of burr formation and appearance. Tests were performed in aluminium and steel. Data obtained was analysed and compared. The experimental setup is desribed and the analysis of AE signals fs explained, formulated and applied. From the analytical model, the effects of drilling conditions such as feed, work piece material and drill diameter were studied. This resulted in the es-tqblishment of empirical type AE equations which incorporate drilling parameters. The ability of buru prediction can be used to control drilling parameters on-line, according to AE values.
A method for predicting bum formation in drilling using an acoustic emission (AE) based technique is proposed and tested. The model development is based on drilling with and without burrs using standard twist drills. The objective of the... more
A method for predicting bum formation in drilling using an acoustic emission (AE) based technique is proposed and tested. The model development is based on drilling with and without burrs using standard twist drills. The objective of the work is to enable on-line prediction of burr formation and appearance.
Tests were performed in aluminium and steel. Data obtained was analysed and compared.
The experimental set-up is described and the analysis of AE signals is explained, formulated and applied.
From the analytic model, the effects of drilling conditions such as feed, work piece material and drill diameter were studied. This resulted in the establishment of empirical type AE equations which
incorporate drilling parameters. The ability of burrs prediction can be used to control drilling parameters on-line, according to AE values.
Tests were performed in aluminium and steel. Data obtained was analysed and compared.
The experimental set-up is described and the analysis of AE signals is explained, formulated and applied.
From the analytic model, the effects of drilling conditions such as feed, work piece material and drill diameter were studied. This resulted in the establishment of empirical type AE equations which
incorporate drilling parameters. The ability of burrs prediction can be used to control drilling parameters on-line, according to AE values.
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Ovarian hyperstimulation syndrome has been described after treatment with exogenous gonadotropins, clomiphene citrate, and gonadotropin-releasing hormone. Spontaneous ovarian hyperstimulation syndrome has not been described before, except... more
Ovarian hyperstimulation syndrome has been described after treatment with exogenous gonadotropins, clomiphene citrate, and gonadotropin-releasing hormone. Spontaneous ovarian hyperstimulation syndrome has not been described before, except in association with hypothyroidism. We report on a case associated with spontaneous pregnancy, occurring in a woman with polycystic ovary disease.
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Over a 2-year period, ultrasound-guided aspiration of painful, presumptively benign ovarian cysts was performed in 18 women < 40 years old. Aspiration was performed either transvaginally (12 patients) or transabdominally (6... more
Over a 2-year period, ultrasound-guided aspiration of painful, presumptively benign ovarian cysts was performed in 18 women < 40 years old. Aspiration was performed either transvaginally (12 patients) or transabdominally (6 patients) depending on the cyst location. Neither anaesthesia nor analgesia were used, and all patients had immediate pain relief, and escaped immediate surgical intervention. None had complications or evidence of malignant cells on cytologic examination, and all were discharged within 24 h of the procedure. The recurrence rate within 1 year of the procedure was 11.1%. The procedure appeared to be a good and safe alternative to surgery.
Research Interests: Pain, Ultrasound, Adolescent, Humans, Female, and 6 moreRecurrence, Adult, Ovarian cysts, Suction, Ovary, and Gynecologic
Eight women (aged 27-43) with reproductive dysfunction who were diagnosed by hysterosalpingogram and hysteroscopy as having a ‘T-shaped’ uterus were operated on using fiberoptic hysteroscopic guidance; the uterine side walls were incised... more
Eight women (aged 27-43) with reproductive dysfunction who were diagnosed by hysterosalpingogram and hysteroscopy as having a ‘T-shaped’ uterus were operated on using fiberoptic hysteroscopic guidance; the uterine side walls were incised until a normal uterine cavity was achieved. The women’s gynecologic and obstetric records were compared before and after the operation. In all the 8 women the operation was
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In this study we tried to determine the factual prevalence of Chlamydia trachomatis seropositive women. Sera of 174 sexually active women of reproductive age who attended the emergency room in our gynecology department were tested by both... more
In this study we tried to determine the factual prevalence of Chlamydia trachomatis seropositive women. Sera of 174 sexually active women of reproductive age who attended the emergency room in our gynecology department were tested by both a species-specific solid-phase enzyme immunoassay (SPEIA, ImmunoComb, Orgenics, Israel) and by an immunoperoxidase assay (IPA). One-hundred and twenty-two of 174 women (70.1%) tested were found positive for C. trachomatis by the IPA test. The SPEIA test identified 41 (33.6%) of those as positive for C. trachomatis and 81 (66.4%) positive for C. pneumoniae. We conclude that the currently used IPA method for chlamydia diagnosis overestimates C. trachomatis infection and its specificity for the diagnosis of C. trachomatis is limited. By using the SPEIA test, it is possible to distinguish between C. trachomatis and C. pneumoniae seropositivity.
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The use of methotrexate (MTX) as a first-line treatment of ectopic pregnancies has become popular recently. This report details a previously unreported complication of MTX treatment. Presumptive ectopic pregnancy with an initial beta-hCG... more
The use of methotrexate (MTX) as a first-line treatment of ectopic pregnancies has become popular recently. This report details a previously unreported complication of MTX treatment. Presumptive ectopic pregnancy with an initial beta-hCG level of 3,500 mIU/ml was treated with a single intramuscular dose of 50 mg/m2 MTX. Three weeks later with a beta-hCG level of 870 mIU/ml, the patient was operated for suspected rupture of ectopic pregnancy. Laparotomy revealed left aborted tubal pregnancy with active bleeding from left fimbria and estimated 2,000 ml of blood in the cul-de-sac. Left salpingectomy was performed. Two days later the patient developed signs of large bowel obstruction. The second laparotomy revealed sigmoid volvulus, that was treated with detorsion of the sigmoid loop. Although generally safe and effective, MTX should be used with utmost care in treatment of ectopic pregnancies.
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This study examines Prolactin and Androgen concentrations in 15 women with a Bartholin's gland abscess and in 15 matched normal controls. The Dehydroepiandrosterone sulfate concentrations were higher in the Bartholin's... more
This study examines Prolactin and Androgen concentrations in 15 women with a Bartholin's gland abscess and in 15 matched normal controls. The Dehydroepiandrosterone sulfate concentrations were higher in the Bartholin's abscess group as compared to the concentrations in the control group [7.0 +/- 3.1 mmol/l versus 4.3 +/- 1.3 mmol/l (p < 0.05), respectively]. The Prolactin and the Testosterone levels did not differ statistically between the two groups.
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Ovarian hyperstimulation syndrome has been described after treatment with exogenous gonadotropins, clomiphene citrate, and gonadotropin-releasing hormone. Spontaneous ovarian hyperstimulation syndrome has not been described before, except... more
Ovarian hyperstimulation syndrome has been described after treatment with exogenous gonadotropins, clomiphene citrate, and gonadotropin-releasing hormone. Spontaneous ovarian hyperstimulation syndrome has not been described before, except in association with hypothyroidism. We report on a case associated with spontaneous pregnancy, occurring in a woman with polycystic ovary disease.
Research Interests:
Prostaglandins, Leukotrienes and Essential Fatty Acids, Volume 170, Issue 5, Pages A1, May 1994, Authors:Zvi Katz, MD; Isaac Blickstein, MD. Journal Home, ... Reply to: The management of prolapse of the umbilical cord. Zvi Katz, MD, Isaac... more
Prostaglandins, Leukotrienes and Essential Fatty Acids, Volume 170, Issue 5, Pages A1, May 1994, Authors:Zvi Katz, MD; Isaac Blickstein, MD. Journal Home, ... Reply to: The management of prolapse of the umbilical cord. Zvi Katz, MD, Isaac Blickstein, MD. No abstract is available. ...
