diff --git a/src/captas.c b/src/captas.c
index 3903c00..ff16b35 100644
--- a/src/captas.c
+++ b/src/captas.c
@@ -1,6 +1,6 @@
 /*
 
- Computer Aided Pressure Transient Analysis (and Simulation?) – CAPTA(S?)
+ Computer Aided Pressure Transient Analysis (and Simulation?) � CAPTA(S?)
      Copyright (C) 2013  Carlos E. Pico
 
     This program is free software: you can redistribute it and/or modify
@@ -534,7 +534,8 @@ void init_parameters(modelparameters *par)
 	par->parnames[PENETRATION_RATIO]       = "b";
 	par->parnames[MIDPOINT_ELEVATION]      = "zw",
 	par->parnames[EFFECTIVE_HEAT_CAPACITY] = "cpt",
-	par->parnames[INITIAL_TEMPERATURE]     = "Ti";
+	par->parnames[INITIAL_TEMPERATURE]     = "Ti",
+	par->parnames[JOULE_THOMSON_COEFFICIENT]    = "ejt";
 
 	/******************** pointers to delta_pwf functions ********************/
 	for(i = 0; i <  NPMODELS; i++){
@@ -683,7 +684,6 @@ void read_inifile(modelparameters *par)
 	par->h       = iniparser_getdouble(ini, "Test description:h",      0.0);
 	par->rw      = iniparser_getdouble(ini, "Test description:rw",     0.0);
 	par->ct      = iniparser_getdouble(ini, "Test description:ct",     0.0);
-	par->ejt     = iniparser_getdouble(ini, "Test description:ejt",    0.0);
 	par->rhosc   = iniparser_getdouble(ini, "Test description:rhosc",  0.0);
 	par->cp      = iniparser_getdouble(ini, "Test description:cp",     0.0);
 
diff --git a/src/models/dTwf.c b/src/models/dTwf.c
index 37f17ec..832f6e5 100644
--- a/src/models/dTwf.c
+++ b/src/models/dTwf.c
@@ -16,7 +16,7 @@
 * Transient temperature behavior and analysis of single-phase liquid-water
 * geothermal reservoirs during drawdown and buildup tests: Part I.
 * Theory, new analytical and approximate solutions.
-* Journal of Petroleum Science and Engineering, 146, 637–656.
+* Journal of Petroleum Science and Engineering, 146, 637�656.
 * https://doi.org/10.1016/j.petrol.2016.08.003
 */
 
@@ -28,21 +28,22 @@
 double dTwf(const modelparameters *p, double t)
 {
     double a, b, cpR, f, d;
-    double k, S, cpt;
+    double k, S, cpt, ejt;
 
     gsl_set_error_handler_off();
 
     k   = p->rpval[PERMEABILITY];
     S   = p->rpval[SKIN_FACTOR];
     cpt = p->rpval[EFFECTIVE_HEAT_CAPACITY];
+    ejt = p->rpval[JOULE_THOMSON_COEFFICIENT];
 
     a   = (p->C2 * p->qB * p->mu) / (k * p->h);
     b   = (p->rw * p->rw * p->phi * p->ct * p->mu ) / (4.0 * k * p->C1);
     cpR = (p->rhosc / p->B) * p->cp / cpt;
-    f   = p->phi * cpR * (p->ejt + 1.0 / (p->rhosc * p->cp / p->B)) - p->ejt;
+    f   = p->phi * cpR * (ejt + 1.0 / (p->rhosc * p->cp / p->B)) - ejt;
     d   = (p->phi * cpR * p->ct)  * a * 0.5;
 
-    return -0.5*a*( -p->ejt*(gsl_sf_expint_E1(b/t) + 2.0*S) - f*gsl_sf_expint_E1(b/t + d) );
+    return -0.5*a*( -ejt*(gsl_sf_expint_E1(b/t) + 2.0*S) - f*gsl_sf_expint_E1(b/t + d) );
 
 }
 /*****************************************************************************/
diff --git a/src/models/modelparam.h b/src/models/modelparam.h
index 31a4a28..c853176 100644
--- a/src/models/modelparam.h
+++ b/src/models/modelparam.h
@@ -30,6 +30,7 @@
 #define MIDPOINT_ELEVATION              18
 #define EFFECTIVE_HEAT_CAPACITY         19
 #define INITIAL_TEMPERATURE             20
+#define JOULE_THOMSON_COEFFICIENT       21
 
 typedef struct
 {
@@ -62,7 +63,6 @@ typedef struct
 		ct,     // total compressibility
 		rw,     // wellbore radius
 		h,      // formation thickness
-		ejt,    // joule-thomson coefficient
 		rhosc,  // density at standard conditions
 		cp;     // specific heat capacity