Water-saving strategies in the mining industry - The potential of mineral processing simulators as a tool for their implementation.

As the mining industry is facing an increasing number of issues related to its fresh water consumption, water-saving strategies are progressively being implemented in the mineral processing plants, often leading to variations in the process water chemistry. However, the impact of water chemistry variations on the process performance is rarely known beforehand, thus creating an obstacle to the implementation of those water-saving strategies. To tackle this problem, the effect the different dissolved species present in the process water have on the processing plant performance must be quantified, and this information must be digitalized in a practical and suitable form to be used in mineral processing simulators. To achieve this goal, a methodology to digitalize the influence of the process water composition on the flotation performance is presented in this paper. Using the flotation of a fluorite ore as case study, the relationship between process water composition and the flotation kinetics of that fluorite ore was determined. This relationship was digitalized in HSC Sim, a mineral processing simulator, turning it into a tool capable of simulating the flotation performance under a variety of process water compositions. Finally, the potential of this new tool to help implementing water-saving strategies on the mine site is discussed, and the challenges that need to be overcome in order to apply this tool at industrial scale are being addressed.

[Radical transurethral resection of the prostate. An alternative therapy for the treatment of prostate cancer]. / Die radikale transurethrale Resektion der Prostata. Eine alternative Operationsmethode zur Behandlung des Prostatakarzinoms.

The value of radical transurethral resection of prostate cancer (TURPC) as an alternative therapy was investigated in this prospective study. From January 1995 to July 2008, 533 patients with a median age of 67 years (range 40-89 years) and with clinically localized prostate cancer were resected by the corresponding author with curative intention. The tumor stages were as follows: pT1 8%; pT2 61%; pT3 31%; G1 2%; G2 80%; G3 18%. TURPC requires continuous low-pressure irrigation with the irrigator liquid level at 10 cm water above the pubic region. It also requires a suprapubic trocar, a resectoscope with a 28F sheath, an autoregulated electrosurgical unit, and video monitoring. The prostate is resected completely with peripheral capsule and seminal vesicles. The specimen is retrieved in fractions for correct histopathological staging. If indicated, laparoscopic staging lymphadenectomy is performed. A secondary session for control of positive margins follows after 8 weeks. The transfusion rate was 1.5%, revision for hemorrhage 2.4%, lung embolism 0.2%, bladder neck incision 14%, grade 2 incontinence 0.6% out of 314, and impotence 30% out of 136. The prostate-specific antigen (PSA) nadir was < or =0.2 ng/ml in 95% of 444 cases. PSA recurrence at 5 years was 6% for pT1, 18% for pT2, and 31% for pT3. Postoperative survival at 10 years was 96% for pT1, 91% for pT2, and 85% for pT3 patients. Prostate cancer can be resected transurethrally with reasonable oncological results. The outcome with respect to survival and PSA recurrence is comparable with the results of other published procedures. Low-pressure irrigation with a suprapubic trocar is mandatory for safe performance.

[Transurethral resection in prostate cancer, a radical procedure. Experience with 1017 cases]. / Resección transuretral en cáncer de próstata, un procedimiento radical. Experiencia con 1017 casos.

OBJECTIVES: From the beginning of TUR in 1931 the reseccionists thought of resecting prostate cancer. Execution however failed for deficient instruments and techniques. The first transurethral resection for prostate cancer: TURPC--was performed at our institution in 1957 by Hans J. Reuter. Low pressure irrigation enabled safe transurethral resection of the prostate including the capsule. Thus we started in 1985 a prospective study to verify TURPC as a radical procedure. METHOD: TURPC requires continuous low pressure irrigation with irrigating reservoir fixed at the operating table. The liquid level within is to maintain less than 20 cm. water above the pubic region in lithotomy position. Continuous flow is maintained by suprapubic trocar and a resectoscope with 28Fr. sheath. An autoregulated electro-surgical unit is indispensable. It automatically adjusts the high-frequency current to suit the cut tissue's electrical resistance for precise cutting. Videomonitoring is mandatory. The prostate is resected completely with its capsule into periprostatic fat together with the seminal vesicles. The specimen is retrieved in fractions to guarantee correct histopathological staging. If indicated laparoscopic staging lymphadenectomy is performed. A secondary session for control of positive margins follows after 12 weeks. RESULTS: From 1985-2004 1,017 patients with a mean age of 68.9 years and with clinically localized prostate cancer were resected by 5 surgeons with curative intention. The cancer stage distribution was in %: T1: 12, T2: 43, T3: 41, T4: 4.--G1: 8, G2: 72, G3: 20. Mortality 1 out of 1,017. Bladder neck incision 8.9%. Incontinence grade 3: none. Postoperative survival over 10 years was 82% in T1, 87% in T2, 81% in T3 and 34% in T4 patients. Biochemical recurrence as of the rise of three consecutive PSA-values was within 5 years 15% in T1, 19% in T2, 27% in T3. CONCLUSIONS: Considering our results we conclude that prostate cancer can be resected transurethrally as radical as with open surgery. The outcome as to survival and PSA-recurrence is comparable, the incontinence rate is less then with open surgery. It is mandatory to have low pressure irrigation with suprapubic trocar, 28Fr. sheath and on autoregulated electrosurgical unit, video monitoring and a well experienced reseccionist.

[Development and usage of a new laser resectoscope]. / Zur Entwicklung und Anwendung eines neuen Laserresektoskops.

BACKGROUND: Endoscopes for the application of laser energy have not been modified substantially for 3 decades. They have two essential disadvantages: the laser probe has no sufficient fixation and irrigation is ineffective in clearing endoscopic vision from hemorrhage. These defects were corrected in cooperation with the R. Wolf Company when developing a new laser resectoscope. In addition the one-handed usage was improved. MATERIAL AND METHOD: The new instrument was used in 71 of the 329 patients undergoing surgery of the prostate with KTP laser by 8 surgeons in our institution. No instrument has been damaged by laser since. Seven of eight surgeons have acknowledged the advantages and approved the new laser endoscope. CONCLUSION: The new laser resectoscope can be recommended to improve the safety of endoscopic laser surgery in general.

[Biography of Phillip Bozzini (1773-1809) an idealist of the endoscopy]. / La biografía de philipp Bozzini (1773-1809) un idealista de la endoscopia.

Philipp Bozzini was born the 25 of May of 1773 in Mainz, Germany. The 12 of June of 1797 obtain the title of medicine doctor. From 1804 it is practically dedicated of complete to the development of its instrument, this have the approximated form of one metallic vase of 35 cm height, had in leather. In its previous face it has a circular opening that is divided vertically by a partition. In left half is the luminance source (a wax candle) and behind is a mirror, that it projects the light produced towards the interior of the corporal cavity to explore. By other half, the observer receives the reflected light and the image of the explored organ. In the later face they adapt according to the cavity diverse specula's, this allow to inspect ear, urethra, feminine bladder, rectum, uterine neck, nasal or wounds. Philipp Bozzini, profit with modest means available at the beginning of XIX century, to demonstrate to the medical world the way of endoscopes. It was with its instrument and ideas, 3/4 of century advanced to the technical and scientific possibilities of the moment. The historians are in agreement, in which this instrument, with artificial light, diverse mirrors and specula's war the beginning of a numerous family of endoscopies.

La vaporización fotoselectiva del adenoma prostático con el ktp-láser (kalium-titanyl-phosphat) de 80 watt y la RTU-P de baja presión hidráulica / The photoselective vaporization of prostate adenoma with the 80 watt ktp-laser (kalium-titanyl-phosphat) and the low hydraulic pressure tur-p

El objetivo de este trabajo prospectivo es determinar la eficacia del método KTP-láser de 80 watt para la vaporización y ablación de la HPB sintomática. También se analizan los resultados al combinar el KTP-láser con la RTU-P y su repercusión sobre la hemoglobina. Material y Método: 300 pacientes con HPB sintomática fueron tratados entre agosto del 2004 y noviembre del 2006 con el KTPláser o combinado con RTU-P. La resección adicional fue efectuada en pacientes con adenomas grandes o por lóbulo medio acentuado. El efecto ablativo fue controlado al final de la operación por medio de TRUS. Resultados: 300 pacientes fueron tratados en 2 grupos. El grupo 1 (n: 50) con sólo tratamiento láser y pequeños adenomas, la hemoglobina se redujo un 3,2 por ciento y nadie requirió una transfusión. El grupo 2 (n: 250) con tratamiento combinado de KTP-láser y RTU-P en adenomas grandes, la hemoglobina se redujo en promedio 15,2 por ciento después de la intervención; 2 pacientes (0,8 por ciento) necesitaron una transfusión. Conclusión: El estudio pone de manifiesto, las ventajas de combinar ambos procedimientos quirúrgicos para obtener un mejor resultado en la ablación del adenoma sobre todo en próstatas de gran tamaño.

The objective of this prospective study is to determine the effectiveness of the 80 watt KTP laser method for the vaporization and ablation of the symptomatic BPH. Also the results when combining the KTP-laser with the TUR-P and their repercussion on the haemoglobin are analysed. Material and Method: 300 patients with symptomatic BPH were treated between august 2004and november 2006 with the KTP-Laser or combined with TUR-P. The additional Resection was carried out in those patients with great adenomas or to have accentuated middle lobule. The ablative effect was controlledat the end of the operation with TRUS (transrectal ultrasound). Results: 300 patients were treated in 2 groups. The group 1 (n: 50) just by laser treatment and small adenomas, the haemoglobin was reduced a 3.2 percent and nobody required a transfusion. Group 2 (n: 250) with combined treatment of KTP-laser and TURP in great adenomas, the haemoglobin was reduced in average 15,2 percent after the intervention; 2 patients (0,8 percent) needed a transfusion. Conclusion: Our study puts of open, the advantages to combine both surgical procedures to mainly obtain a better result in the ablation of the prostate adenoma in prostates of great size.

[The low hydraulic pressure transurethral resection of the prostate results in 340 patients with great adenomas]. / La resección transuretral de la próstata de baja presión hidráulica, resultados en 340 pacientes con adenomas grandes.

INTRODUCTION: the transurethral resection of prostate TURP is the elective treatment for the small and medium adenomas. In this study they analyse the effectiveness, the results and the postoperative morbidity in the resection of the great adenomas. PATIENTS AND METHOD: We study 340 patients with great adenomas and symptomatic infravesical obstruction that were operated with the low hydraulic pressure RTUP between August of 1999 and June of 2006. RESULTS: Average Age of the patients 69 years (range 51-89). Prostate volume by TRUS, 107 ml (70-204). PSA 7,94 ng/ml (0,71-26,4). Weight of the resected fragments: 74,5gr. (50-160), time of the intervention 65 min. (35-155), postoperative urethral catheterisation 1.7 days (1-8), suprapubic derivation 6.5 days (5-15), the duration of hospital stay after surgery were 8 days (7-16), peak flow pre-op. 11.2 ml/sec. (5-15,7), post-operative 19.7 ml/sec. (7-41,3). There were no cases of TURP syndrome in this group. Operative complications: Urinary infection without fever (bacteria >100.000) 95 patients (27.9%), bladder derivation by preoperative urinary retention 53 patients (15,6%). 18 patients (5,3%) with postoperative urinary retention. 11 patients (3,2%), with infection and fever >38 degrees C. 7 patients (2%) with postoperative bladder bleeding, 2 patients (0,6%) with urethral lesion. 1 patient (0.3%), with massive scrotal hematoma (after vasectomy). Control of the pre and post operative hemoglobin: Hemoglobin pre-op 15 g/dl (12-19,3), hemoglobin post-op 11,5 g/dl (7,6-16,4), difference of (- 3,5g/dl) 23,3%. In only 29 patients (8.5%) it was necessary to carry out a sanguineous transfusions (heterolog) of 2 to 4 EC (500 ml), the TRUS was 125 ml, weight of the fragments 90 gr. (52-140), the hemoglobin pre-op was 14,72g/dl and post-op of 8,8g/dl with a difference of (- 5,92g/dl) 40.2%. CONCLUSIONS: The video assisted low hydraulic pressure TURP, is an effective method in the surgical treatment of great prostate adenomas. The severe postoperative complications are little, and in 311 patients (91.5%) it was not necessary sanguineous transfusion. The stationary treatment and the urethral catheterisation is smaller in comparison with the open adenomectomy.

Understanding of hazardous waste incineration through computational fluid-dynamics simulation.

Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types. However, the complex transport and chemical processes within the kiln system are still not well understood. The complete destruction of hazardous compounds depends very much on gas mixing behavior of different air and waste streams, the distribution of gas temperature and residence time within the kiln and the secondary combustion chamber (SCC). Due to large variations of waste types and difficulties in feed characterization (physical, chemical and thermal properties), the incineration process meets great challenges in a smooth operation, with substantial fluctuations of gas temperatures within the system. The temperature fluctuations lead to uncertainties in the process chemistry and difficulties in emission control. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control for lower emissions and a better environmental impact. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the kiln behavior in relation to better process control. One of the focuses was on the process simulation by using Computational Fluid-dynamics (CFD) to characterize gas flow, temperature distribution and waste combustion in the rotary kiln incinerator. Temperature measurement of the operating rotary kiln incinerator at AVR-Chemie, located at the Rotterdam harbor in The Netherlands, was conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will address the environmental issues related to the hazardous waste incineration, and summarize the results from the current research project for the simulation of gas flow and mixing, combustion heat transfer, and new ideas to use CFD simulation results for process control of an incineration plant.

The development of urological endoscopy in America.

This article deals with the history of medicine in American urology, where endoscopy is a very important subject. The development of endoscopy in America unrolled in three phases: the acquisition of European techniques and instruments, realization of the ideas of American researchers, and original creations that forwarded endoscopy considerably. European instruments were acquired in the nineteenth century, culminating in the instruments developed by Max Nitze. When Wappler started the production of endoscopes in 1905, they were the basis for the development of numerous modifications and innovations such as electrosurgery, developed by Beer in 1910, with the Resonator created by Wappler; the resectoscope, invented by Stern and McCarthy in 1931; "cold light" using glass fibers for illumination, described by ACMI in 1960; the flexible fiber ureterorenoscope, described by Marshall in 1960; and fluorescence cystoscopy, introduced by I. M. Bush and W. F. Whitmore in 1964.

Prostatic hyperplasia over 80 grams weight, is transurethral resection an adequate procedure? Results of a prospective study.

A prospective study of transurethral resection with continuous low pressure irrigation was undertaken to find out, whether large prostates can be operated transurethrally without undue risk. Since 1986, the beginning of the study, 121 prostates with adenomas over 80 grams weight (> 80 g group) were resected. The mean age of the patients was 70.1 years, the mean weight of the resected prostate tissue was 104 grams in 66 minutes. The postoperative mortality was below 1% (1 patient). 17 patients (14%) needed blood transfusion, 11 patients had peroperative hemodilution. Even with large prostate, considering the rather high mean age of the patients treated, there is no considerably elevated operating risk, when large prostates are resected transurethrally. It however has to be emphasized, that this is achieved only with continuous low pressure irrigation and the loop of a 28 Fr. standard resectoscope in combination with an automatically regulated electrosurgical unit.

[Total transurethral electroresection of carcinoma of the prostate]. / Electrorresección transuretral total del carcinoma de la próstata.

Transurethral resection of the prostatic carcinoma was performed here most completely at a time already when radical surgical prostatectomy was not a rather new procedure. The preliminary evaluation of 150 cases of all stages (T1-4) showed a 5 year survival rate of almost 80% with post-operative complications comparable to transurethral prostatectomy of the adenoma.

[Transurethral low pressure prostatectomy. Technic, blood loss and water syndrome]. / Die transurethrale Niederdruckprostatektomie. Technik, Blutverlust und Wassersyndrom.

The new procedure for transurethral prostatectomy (TURP with physiologic low pressure irrigation and continuous aspiration of irrigant) reduces complication and mortality in respect to surgical prostatectomy: In 2.500 TURP clinical significant pulmonary embolism was not realised, mortality was 0.3%. The average blood loss was 238 cc. by a weight of 44.8 g, blood transfusion were necessary in only 4%. Low pressure TURP can be performed in most high risk patients, this is not true for open surgical prostatectomy, which has a rate of complications up to 25%. Postoperative recovery and late results are definitely improved by low pressure TURP, teaching is facilitated.

[Diagnostic and surgical endoscopy of the ureter and kidney. Initial experiences with uretero-renoscopy]. / Die diagnostische und operative Endoskopie von Ureter und Niere. Ereste Erfahrungen mit der Uretero-Renoskopie.

The new method of uretero-renoscopy with rigid endoscopes has extended the possibilities for endoscopic diagnosis and procedures in the ureter and kidney. Our first experiences in 37 patients are absolutely positive even if one considers the initial difficulties passing the ostium. This method, introduced by E. Perez-Castro can be recommended to skilled endoscopists if the basic principles of endoscopy are strictly observed (no hard pushing of instruments, continuous optical and x-ray control with contrast medium and physiologic low pressure irrigation). This advice must be observed even more so in operative uretero-renoscopy, where instruments and techniques are still at an initial stage. It was possible to extract transurethrally nearly half of the ureteral calculi prepared for surgical procedure. Biopsy, coagulation and other methods used in connection with operative cystoscopy can be applied.

Clinical value of different methods for determination of acid phosphatase in prostatic cancer.

The availability of a radioimmunoassay (RIA) and an enzyme immunoassay (EIA) for the prostate specific acid phosphatase required a study to compare these techniques with the conventional colorimetric assay. Our study is based on examinations of 188 normal persons and 136 patients with carcinoma of the prostate. The advantage of the immunologic methods - RIA and EIA - lies in their stable immunologic activity and their high specificity. However, RIA and EIA are not screening methods for incidental carcinoma because of their low sensitivity for stage-A tumors. Their good sensitivity at lower ranges of concentration makes them suitable for checking the course of a prostatic carcinoma during therapy. The level of prostatic acid phosphatase may allow conclusions about intra-or extracapsular growth of the prostatic carcinoma.